[Bf-committers] Quit Blender!

[Antony Riakiotakis]

In the spirit of the latest short movie, and after getting jealous of
MacOsX I thought this would be a nice little afternoon project. So, at
long last, quit blender for windows:

http://www.pasteall.org/30067/diff

This patch adds an interface that OS specific windows can implement to
spawn a message box asking for confirmation to quit. Only tested on
windows, can other OS maintainers also check if it compiles OK? The
interface is currently implemented only for Windows.