"Professional CMake" book suggest the following:
"Targets should build successfully with or without compiler support for precompiled headers. It
should be considered an optimization, not a requirement. In particular, do not explicitly include a
precompile header (e.g. stdafx.h) in the source code, let CMake force-include an automatically
generated precompile header on the compiler command line instead. This is more portable across
the major compilers and is likely to be easier to maintain. It will also avoid warnings being
generated from certain code checking tools like iwyu (include what you use)."
Therefore, removed the "#include <PreCompiled.h>" from sources, also
there is no need for the "#ifdef _PreComp_" anymore
Due to a flaw in the QUiLoader, UiLoader were loading all designer plugins
it can find in QApplication::libraryPaths(). This in general a bad
practice and leads to bugs due to some plugins may perform some unexpected
actions upon load which may interfere with FreeCAD's functionality.
To avoid such problems reset the libraryPaths before creation of a
UiLoader object.
Also move setLanguageChangeEnabled(true) into constructor due to it's
called every time it's being instanced anyway.
See: https://github.com/FreeCAD/FreeCAD/issues/8708
