Incorrect OS identification

[RElesgoe]

PvPGN thinks all of the Windows OSs are Windows XP

[HarpyWar]

Changed based on info from http://msdn.microsoft.com/en-us/library/windows/desktop/ms724833(v=vs.85).aspx

[RElesgoe]

Have you tested this commit with Windows 8.1 yet? The statement on Microsoft's website suggest using the new Version Helper functions instead of GetVersion and GetVersionEx: http://msdn.microsoft.com/en-us/library/windows/desktop/dn424972(v=vs.85).aspx

[HarpyWar]

Yes, on Windows "8.1" it determines as "8" now.

[RElesgoe]

We should add code to check for versions higher than 8.1 in case future servers are on older versions of this PvPGN. If another Windows is released, the current code will assume 8.1.

IsWindowsVersionOrGreater(6, 4, 0)
Should then go to the default case