Reviewed-by: Trust Me

- clear up some Q_OS_LINUX vs. Q_OS_UNIX
- clear up Q_WS_* vs. Q_OS_* (relatively theoretical exercise)
- use proper #if-#else cascades instead of free-standing #ifs

double click on the "<...>" line

Details:  missing some more information, though..

Conflicts:

	src/plugins/debugger/cdbdebugengine.cpp