Allows
* projects linking to KCoreAddons to hide deprecated API up to a
given version or silence deprecation warnings before a given version,
using
-DKCOREADDONS_DISABLE_DEPRECATED_BEFORE_AND_AT
-DKCOREADDONS_DEPRECATED_WARNINGS_SINCE
-DKCOREADDONS_NO_DEPRECATED_WARNINGS
-DKCOREADDONS_NO_DEPRECATED
or
-DKF_DISABLE_DEPRECATED_BEFORE_AND_AT
-DKF_DEPRECATED_WARNINGS_SINCE
-DKF_NO_DEPRECATED_WARNINGS
-DKF_NO_DEPRECATED
* to build KCoreAddons optionally with deprecated API excluded from
the build, using "EXCLUDE_DEPRECATED_BEFORE_AND_AT" cmake argument.