Added support to compile with Python2.7 on Linux
Windows support will come later as discussed in
https://phabricator.kde.org/D12838. To compile use the
-DENABLE_PYTHON_2 flag. Python 3 is still the default.
For the plugins to work correctly we need the tollius and pathlib
modules through pip.
Differential Revision: https://phabricator.kde.org/D12838
(cherry picked from commit 6509644e3cb89610fce1f2925b0126c9bc1439c0)