Docstrings, qmake-project files, qt5

Hello Oro,

here is the new pull request. As discussed I have tried to clean up the commits a bit.
The QMake project files are tested on Linux, Windows and MacOSX.

With your CMake project files I observed a linker error for PythonQt_QtAll on my virtual windows with Qt4.8 (not linking against OpenGL), but thats perhaps a problem of my outdated Qt version (4.8.4).

Regards,
Melven