From Valeri Fine:

TGQt.cxx,GQtGUI.cxx, TGQt.h:
- protection: SetDynamicPath caused SegFault on Win32
- Add "const" to some methods as needed
- Activate setCompositionMode for Qt 4.1.2
- Add Getter/Setter for the alpha channel with Qt 4.1.2

TQtClientGuard.cxx:
- Compilation warning with Qt 4.1.2

TQtBrsuh:
- Add "const" to some methods as needed


git-svn-id: http://root.cern.ch/svn/root/trunk@15222 27541ba8-7e3a-0410-8455-c3a389f83636