Fixing Qt5 issues with LCG >= LCG_91 (fixes ATLINFR-2218) (NEW VERSION!)
This will fix ATLINFR-2218.
Two new modules have been defined in AtlasLCG/modules, one for the package libxkbcommon and one for the glib one.Also, the environment variable QT_XKB_CONFIG_ROOT needed by Qt5 at runtime is defined with the libxkbcommon lib path.
NOTE: This is used by athena!8683