[Releasing] Platform and Compiler configurations for Qt 5.0 beta release

[kai.koehne at nokia.com]

> Just FYI. I can't get Qt 5 pulled from current git to build with MinGW 4.6.
> Phonon is trying to include dsound.h which is not available. Then JSBackend is
> trying to include private/v8.h which is nowhere to be found either. Maybe I
> just caught it in the middle of changes?

When errors like the latter happens to me, it's usually because I've the wrong qmake in the path. 

Other things to check
- did you run configure from top level at least once?
- are you trying to do a shadow build ? Is your source directory clean?

Hope that helps,

Kai