Adds Windows Server 2012 and Windows 8 detection to os_getversion as per the details from http://msdn.microsoft.com/en-us/library/windows/desktop/ms724833(v=vs.85).aspx
Adds OS X 10.8 detection yet in a different way than currently as I believe Gestalt has been deprecated in 10.8 and generates warnings. I have never tested this code on 10.8 yet have on other versions.
Merged in liamdevine/premake-dev-foo (pull request #30)
Improved os.getversion() with support for Windows 8
Fix broken Makefile defines