Added new macros for Qt5 support
- Added new macros for Qt5 support, %mingw32_qmake_qt5, %mingw64_qmake_qt5,
%mingw_qmake_qt4 and %mingw_qmake_qt5
- It isn't necessary to call %mingw32_env / %mingw64_env any more
in the %mingw32_qmake_qt4 and %mingw64_qmake_qt4 macros