diff --git a/CMakeLists.txt b/CMakeLists.txt
index 0461ae0f2..52dc539e2 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,411 +1,424 @@
 project(labplot2)
 
 # minimum 3.2.0 for FindGSL.cmake
 cmake_minimum_required (VERSION 3.2.0 FATAL_ERROR)
 set(CMAKE_C_STANDARD 99)
 set(CMAKE_C_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_STANDARD 11)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFF)
 
 set(QT_MINIMUM_VERSION 5.6.0)
 set(KF5_MIN_VERSION "5.16.0")
 
 find_package(ECM 1.3.0 REQUIRED NO_MODULE)
 set(CMAKE_MODULE_PATH ${ECM_MODULE_PATH} ${ECM_KDE_MODULE_DIR})
 # build type: "release", "debug", "debugfull"
 string (TOLOWER "${CMAKE_BUILD_TYPE}" CMAKE_BUILD_TYPE)
 find_package(Qt5 ${QT_MIN_VERSION} NO_MODULE REQUIRED COMPONENTS
 	Concurrent
 	Gui
 	PrintSupport
 	Sql
 	Svg
 	Widgets
 	Test
 	SerialPort
 )
 
 find_package(KF5 ${KF5_MIN_VERSION} REQUIRED COMPONENTS
 	Archive
 	Completion
 	Config
 	ConfigWidgets
 	CoreAddons
 	Crash
 	DocTools
 	I18n
 	IconThemes
 	TextWidgets
 	WidgetsAddons
 	XmlGui
 OPTIONAL_COMPONENTS
 	NewStuff
 	Service
 	Parts
 	SyntaxHighlighting
 )
 IF (Qt5SerialPort_FOUND)
         MESSAGE (STATUS "Found Qt5 SerialPort")
 ELSE ()
         MESSAGE (STATUS "Qt5 SerialPort not found")
 ENDIF ()
 IF (KF5NewStuff_FOUND)
         MESSAGE (STATUS "Found KF5 new stuff")
 	add_definitions (-DHAVE_KF5_NEW_STUFF)
 ELSE ()
         MESSAGE (STATUS "KF5 new stuff not found")
 ENDIF ()
 IF (KF5SyntaxHighlighting_FOUND)
         MESSAGE (STATUS "Found KF5 syntax highlighting")
 	add_definitions (-DHAVE_KF5_SYNTAX_HIGHLIGHTING)
 ELSE ()
         MESSAGE (STATUS "KF5 syntax highlighting not found")
 ENDIF ()
 
 find_package(BISON REQUIRED)
 
 include(FeatureSummary)
 include(ECMAddAppIcon)
 include(ECMInstallIcons)
 include(KDEInstallDirs)
 include(KDECompilerSettings)
 include(KDECMakeSettings)
 
 ### compiler flags ######################################
 set (GENERIC_FLAGS "-Wall -Wextra -Wundef -Wpointer-arith -Wunreachable-code -Wunused -Wdeprecated-declarations -fno-omit-frame-pointer -fstack-protector")
 set (GENERIC_GNU_FLAGS "-O2 -Wcast-align -Wswitch-enum -fvisibility=default")
 set (GENERIC_C_FLAGS "${GENERIC_FLAGS} -fno-exceptions")
 # liborigin needs exceptions
 set (GENERIC_CXX_FLAGS "${GENERIC_FLAGS} -fexceptions")
 
 if ("${CMAKE_C_COMPILER_ID}" MATCHES "GNU")
 	message(STATUS "GNU C compiler detected, adding compile flags")
 	set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${GENERIC_C_FLAGS} ${GENERIC_GNU_FLAGS}")
 elseif ("${CMAKE_C_COMPILER_ID}" MATCHES "Clang")
 	message(STATUS "Clang C compiler detected, adding compile flags")
 	set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -D_GNU_SOURCE ${GENERIC_C_FLAGS} ${GENERIC_GNU_FLAGS}")
 elseif ("${CMAKE_C_COMPILER_ID}" MATCHES "Intel")
 	message(STATUS "Intel C compiler detected, adding compile flags")
 	set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -D_GNU_SOURCE -O3 ${GENERIC_C_FLAGS}")
 elseif ("${CMAKE_C_COMPILER_ID}" MATCHES "PGI")
 	message(STATUS "PGI C compiler detected, adding compile flags")
 	set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -D_GNU_SOURCE -O3 -D__GCC_ATOMIC_TEST_AND_SET_TRUEVAL=1 -Minform=inform -Mbounds -Mchkstk")
 # " x" postfix to work around a bug in CMake that causes "MSVC" to translate to something completely different
 elseif (("${CMAKE_C_COMPILER_ID} x" MATCHES "MSVC") OR MSVC)
 	message(STATUS "MSVC C compiler detected, adding compile flags")
 	set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -O2 -W3")
 	set(MSVC_FOUND TRUE)
 else ()
 	message(STATUS "UNKNOWN C compiler, adding compile flags")
 	set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${GENERIC_C_FLAGS}")
 endif()
 
 if ("${CMAKE_CXX_COMPILER_ID}" MATCHES "GNU")
 	message(STATUS "GNU C++ compiler detected, adding compile flags")
 	set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${GENERIC_CXX_FLAGS} ${GENERIC_GNU_FLAGS}")
 elseif ("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang")
 	message(STATUS "Clang C++ compiler detected, adding compile flags")
 	set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -D_GNU_SOURCE ${GENERIC_CXX_FLAGS} ${GENERIC_GNU_FLAGS}")
 elseif ("${CMAKE_CXX_COMPILER_ID}" MATCHES "Intel")
 	message(STATUS "Intel C++ compiler detected, adding compile flags")
 	set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -D_GNU_SOURCE -std=c++11 ${GENERIC_CXX_FLAGS}")
 	#-std=c++0x comes with cmake's general flags, deprecated in icc, remove it
 	string(REPLACE "-std=c++0x" "" CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS})
 elseif ("${CMAKE_CXX_COMPILER_ID}" MATCHES "PGI")
 	message(STATUS "PGI C++ compiler detected, adding compile flags")
 	set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -D_GNU_SOURCE -O3 -std=c++11 -D__GCC_ATOMIC_TEST_AND_SET_TRUEVAL=1 -Minform=inform -Mbounds -Mchkstk")
 # " x" postfix to work around a bug in CMake that causes "MSVC" to translate to something completely different
 elseif (("${CMAKE_CXX_COMPILER_ID} x" MATCHES "MSVC") OR MSVC)
 	message(STATUS "MSVC C++ compiler detected, adding compile flags")
 	set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -O2 -W3")
 	set(MSVC_FOUND TRUE)
 else ()
 	message(STATUS "UNKNOWN C++ compiler, adding compile flags")
 	set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${GENERIC_CXX_FLAGS}")
 endif ()
 
 ##########################################################ESC[m
 
 
 add_definitions (${QT_DEFINITIONS} ${QT_QTDBUS_DEFINITIONS})
 include_directories (${QDBUS_INCLUDE_DIRS} ${CMAKE_SOURCE_DIR} ${CMAKE_BINARY_DIR})
 set(CMAKE_MODULE_PATH ${CMAKE_SOURCE_DIR}/cmake ${CMAKE_MODULE_PATH})
 add_definitions (-DLVERSION=\"2.6.0\")
 # add_definitions (-DLDEBUG='1')
 set(BUILD_SHARED_LIBS true)
 
 cmake_policy(SET CMP0002 OLD)
 IF (CMAKE_VERSION VERSION_EQUAL "3.3" OR CMAKE_VERSION VERSION_GREATER "3.3")
 	cmake_policy(SET CMP0063 NEW)
 ENDIF()
 
 if (CMAKE_VERSION VERSION_GREATER "3.5")
   set(ENABLE_CLANG_TIDY OFF CACHE BOOL "Add clang-tidy automatically to builds")
   if (ENABLE_CLANG_TIDY)
     find_program (CLANG_TIDY_EXE NAMES "clang-tidy" PATHS /usr/bin)
     if (CLANG_TIDY_EXE)
       message(STATUS "Clang-tidy supported, found and enabled: ${CLANG_TIDY_EXE}")
       set(CLANG_TIDY_CHECKS "-*,modernize-*")
       set(CMAKE_CXX_CLANG_TIDY "${CLANG_TIDY_EXE};-checks=${CLANG_TIDY_CHECKS};-header-filter='${CMAKE_SOURCE_DIR}/*'"
         CACHE STRING "" FORCE)
     else()
       message(AUTHOR_WARNING "clang-tidy not found!")
       set(CMAKE_CXX_CLANG_TIDY "" CACHE STRING "" FORCE) # delete it
     endif()
    else()
     message(STATUS "Clang-tidy supported but disabled")
   endif()
 endif()
 
 ### Options ######################################
 option(ENABLE_CANTOR "Build with Cantor support" ON)
 option(ENABLE_FFTW "Build with FFTW support" ON)
 option(ENABLE_HDF5 "Build with HDF5 support" ON)
 option(ENABLE_NETCDF "Build with NetCDF support" ON)
 option(ENABLE_FITS "Build with FITS support" ON)
 option(ENABLE_LIBCERF "Build with libcerf support" ON)
 option(ENABLE_LIBORIGIN "Build with liborigin support" ON)
 option(ENABLE_ROOT "Build with ROOT (CERN) support" ON)
 option(ENABLE_TESTS "Build with tests" ON)
 option(ENABLE_MQTT "Build with MQTT support" ON)
 
 ### OS macros ####################################
 IF (WIN32)
 	add_definitions (-DHAVE_WINDOWS)
 ENDIF ()
 
 ### GSL (required) ###############################
 FIND_PACKAGE(GSL REQUIRED)
 
 ### liborigin (included) ###############################
 IF (ENABLE_LIBORIGIN)
 	add_definitions (-DHAVE_LIBORIGIN)
 
 	IF (CMAKE_BUILD_TYPE STREQUAL "debug" OR CMAKE_BUILD_TYPE STREQUAL "debugfull")
 		MESSAGE (STATUS "Origin project import (through internal liborigin) enabled (parser logging enabled)")
 		SET (ENABLE_ORIGIN_PARSER_LOG TRUE)
 	ELSE ()
 		MESSAGE (STATUS "Origin project import (through internal liborigin) enabled (parser logging disabled)")
 	ENDIF ()
 ELSE ()
 	MESSAGE (STATUS "Origin project import disabled")
 ENDIF ()
 
 ### Cantorlibs (optional) ###############################
 IF (ENABLE_CANTOR)
 FIND_LIBRARY (CANTOR_LIBS cantorlibs)
 FIND_PATH (CANTOR_INCLUDE_DIR cantor/worksheetaccess.h
 	/usr/include
 	/usr/local/include
 )
 IF (CANTOR_LIBS AND CANTOR_INCLUDE_DIR AND KF5Service_FOUND AND KF5Parts_FOUND)
 	SET (CANTOR_LIBS_FOUND TRUE)
 ELSE ()
 	SET (CANTOR_LIBS_FOUND FALSE)
 	SET (CANTOR_LIBS "")
 ENDIF()
 IF (CANTOR_LIBS_FOUND)
 	MESSAGE (STATUS "Found Cantor Library: ${CANTOR_INCLUDE_DIR} ${CANTOR_LIBS}")
 	add_definitions (-DHAVE_CANTOR_LIBS)
 ELSE ()
 	MESSAGE (STATUS "Cantor Library not found.")
 ENDIF ()
 ELSE ()
 	MESSAGE (STATUS "Cantor Library DISABLED.")
 ENDIF ()
 
 ### FFTW (optional) #####################################
 IF (ENABLE_FFTW)
 FIND_LIBRARY (FFTW_LIBRARIES fftw3
         PATHS
         /usr/lib
         /usr/local/lib
 )
 FIND_PATH (FFTW_INCLUDE_DIR fftw3.h
 	/usr/include
 	/usr/local/include
 )
 IF (FFTW_LIBRARIES AND FFTW_INCLUDE_DIR)
 	SET (FFTW_FOUND TRUE)
 ELSE ()
 	SET (FFTW_FOUND FALSE)
 ENDIF ()
 IF (FFTW_FOUND)
 	MESSAGE (STATUS "Found FFTW 3 Library: ${FFTW_INCLUDE_DIR} ${FFTW_LIBRARIES}")
 	add_definitions (-DHAVE_FFTW3)
 ELSE ()
 	MESSAGE (STATUS "FFTW 3 Library not found.")
 ENDIF ()
 ELSE ()
 	MESSAGE (STATUS "FFTW 3 Library DISABLED.")
 ENDIF ()
 
 ### HDF5 (optional) ##############################
 IF (ENABLE_HDF5)
 FIND_PACKAGE(HDF5 COMPONENTS C)
 IF (HDF5_FOUND)
 	add_definitions (-DHAVE_HDF5)
 	include_directories (${HDF5_INCLUDE_DIRS})
 ELSE ()
 	MESSAGE (STATUS "Hierarchical Data Format (HDF5) Library not found.")
 ENDIF ()
 ELSE ()
 	MESSAGE (STATUS "Hierarchical Data Format (HDF5) Library DISABLED.")
 ENDIF ()
 
 ### NETCDF (optional) #############################
 IF (ENABLE_NETCDF)
 FIND_LIBRARY (NETCDF_LIBRARY netcdf
 	PATHS
 	/usr/lib
 	/usr/local/lib
 )
 FIND_PATH (NETCDF_INCLUDE_DIR netcdf.h
 	/usr/include
 	/usr/local/include
 )
 IF (NETCDF_LIBRARY AND NETCDF_INCLUDE_DIR)
 	SET (NETCDF_FOUND TRUE)
 ELSE ()
 	SET (NETCDF_FOUND FALSE)
 ENDIF ()
 IF (NETCDF_FOUND)
 	MESSAGE (STATUS "Found Network Common Data Format (NetCDF) Library: ${NETCDF_INCLUDE_DIR} ${NETCDF_LIBRARY}")
 	add_definitions (-DHAVE_NETCDF)
 ELSE ()
 	MESSAGE (STATUS "Network Common Data Format (NetCDF) Library not found.")
 ENDIF ()
 ELSE ()
 	MESSAGE (STATUS "Network Common Data Format (NetCDF) Library DISABLED.")
 ENDIF ()
 
 ### MQTT (optional) ###############################
 IF (ENABLE_MQTT)
 find_package(Qt5 ${QT_MIN_VERSION} NO_MODULE COMPONENTS
 OPTIONAL_COMPONENTS
 	Mqtt
 )
 IF (Qt5Mqtt_FOUND)
 	MESSAGE (STATUS "Found MQTT")
 	add_definitions (-DHAVE_MQTT)
 ELSE ()
 	MESSAGE (STATUS "MQTT Library not found.")
 ENDIF ()
 ELSE ()
 	MESSAGE (STATUS "MQTT Library DISABLED.")
 ENDIF ()
 
 ### FITS (optional) ###############################
 IF (ENABLE_FITS)
 FIND_LIBRARY (CFITSIO_LIBRARY cfitsio
 	PATHS
 	/usr/lib
 	/usr/local/lib
 	$ENV{CFITSIO}
 )
 FIND_PATH (CFITSIO_INCLUDE_DIR fitsio.h
 	/usr/include
 	/usr/include/cfitsio
 	/usr/local/include
 	$ENV{CFITSIO}
 )
 IF (CFITSIO_LIBRARY AND CFITSIO_INCLUDE_DIR)
         SET (CFITSIO_FOUND TRUE)
 ELSE ()
         SET (CFITSIO_FOUND FALSE)
 ENDIF ()
 IF (CFITSIO_FOUND)
 	MESSAGE (STATUS "Found Flexible Image Transport System Data Format (FITS) Library: ${CFITSIO_INCLUDE_DIR} ${CFITSIO_LIBRARY}")
 	add_definitions (-DHAVE_FITS)
 	include_directories (${CFITSIO_INCLUDE_DIR})
 ELSE ()
 	MESSAGE (STATUS "Flexible Image Transport System Data Format (FITS) Library not found.")
 ENDIF ()
 ELSE ()
 	MESSAGE (STATUS "Flexible Image Transport System Data Format (FITS) Library DISABLED.")
 ENDIF ()
 
 ### LIBCERF (optional) #############################
 IF (ENABLE_LIBCERF)
 FIND_LIBRARY (LIBCERF_LIBRARY cerf
 	PATHS
 	/usr/lib
 	/usr/local/lib
 )
 FIND_PATH (LIBCERF_INCLUDE_DIR cerf.h
 	/usr/include
 	/usr/local/include
 )
 IF (LIBCERF_LIBRARY AND LIBCERF_INCLUDE_DIR)
 	SET (LIBCERF_FOUND TRUE)
 ELSE ()
 	SET (LIBCERF_FOUND FALSE)
 ENDIF ()
 IF (LIBCERF_FOUND)
 	MESSAGE (STATUS "Found libcerf Library: ${LIBCERF_INCLUDE_DIR} ${LIBCERF_LIBRARY}")
 	add_definitions (-DHAVE_LIBCERF)
 ELSE ()
-	MESSAGE (STATUS "libcerf Library not found.")
+	MESSAGE (STATUS "libcerf library not found.")
 ENDIF ()
 ELSE ()
-	MESSAGE (STATUS "libcerf Library DISABLED.")
+	MESSAGE (STATUS "libcerf library DISABLED.")
 ENDIF ()
 
 IF (ENABLE_ROOT)
 FIND_PACKAGE(ZLIB)
 FIND_LIBRARY(LZ4_LIBRARY lz4
 	PATHS
 	/usr/lib
 	/usr/local/lib
 )
 FIND_PATH (LZ4_INCLUDE_DIR lz4.h
 	/usr/include
 	/usr/local/include
 )
 IF (LZ4_LIBRARY AND LZ4_INCLUDE_DIR)
+	IF (EXISTS "${LZ4_INCLUDE_DIR}/lz4.h")
+		file(STRINGS "${LZ4_INCLUDE_DIR}/lz4.h" LZ4_VERSION_MAJOR REGEX "^#define LZ4_VERSION_MAJOR.*")
+		file(STRINGS "${LZ4_INCLUDE_DIR}/lz4.h" LZ4_VERSION_MINOR REGEX "^#define LZ4_VERSION_MINOR.*")
+		file(STRINGS "${LZ4_INCLUDE_DIR}/lz4.h" LZ4_VERSION_RELEASE REGEX "^#define LZ4_VERSION_RELEASE.*")
+		string(REGEX REPLACE ".*[ ].*([0-9]+).*$" "\\1" LZ4_VERSION_MAJOR "${LZ4_VERSION_MAJOR}")
+		string(REGEX REPLACE ".*[ ].*([0-9]+).*$" "\\1" LZ4_VERSION_MINOR "${LZ4_VERSION_MINOR}")
+		string(REGEX REPLACE ".*[ ].*([0-9]+).*$" "\\1" LZ4_VERSION_RELEASE "${LZ4_VERSION_RELEASE}")
+
+		MESSAGE (STATUS "Found LZ4 library: ${LZ4_INCLUDE_DIR} ${LZ4_LIBRARY} (found version \"${LZ4_VERSION_MAJOR}.${LZ4_VERSION_MINOR}.${LZ4_VERSION_RELEASE}\")")
+	ELSE ()
+		MESSAGE (STATUS "Found LZ4 library: ${LZ4_INCLUDE_DIR} ${LZ4_LIBRARY} (version unknown)")
+	ENDIF ()
 	SET (LZ4_FOUND TRUE)
-	MESSAGE (STATUS "Found LZ4 library: ${LZ4_INCLUDE_DIR} ${LZ4_LIBRARY}")
 ELSE ()
+	MESSAGE (STATUS "LZ4 library not found.")
 	SET (LZ4_FOUND FALSE)
 ENDIF ()
 IF (ZLIB_FOUND AND LZ4_FOUND)
+	MESSAGE (STATUS "ZIP libraries ZLIB and LZ4 (needed for ROOT importer) found.")
 	add_definitions (-DHAVE_ZIP)
 ELSE ()
-	MESSAGE (STATUS "ZIP libraries not found.")
+	MESSAGE (STATUS "ZIP libraries ZLIB and LZ4 (needed for ROOT importer) not found.")
 ENDIF ()
 ELSE ()
 	MESSAGE (STATUS "ROOT (CERN) importer DISABLED.")
 ENDIF ()
 
 #################################################
 include(CheckFunctionExists)
 
 CHECK_FUNCTION_EXISTS(random HAVE_RANDOM_FUNCTION)
 #################################################
 FIND_PATH (XLOCALE_INCLUDE_DIR xlocale.h
 	/usr/include
 	/usr/local/include
 )
 IF (XLOCALE_INCLUDE_DIR)
 	add_definitions (-DHAVE_XLOCALE)
 	include_directories (${XLOCALE_INCLUDE_DIR})
 ENDIF()
 
 add_subdirectory(data)
 add_subdirectory(doc)
 add_subdirectory(icons)
 add_subdirectory(src)
 
 IF (ENABLE_LIBORIGIN)
 	add_subdirectory(liborigin)
 ENDIF ()
 
 if (ENABLE_TESTS)
     enable_testing(true)
     add_subdirectory(tests)
 endif()
 
 install(FILES org.kde.labplot2.appdata.xml DESTINATION ${KDE_INSTALL_METAINFODIR})
 feature_summary(WHAT ALL)