* Fixes virtual memory support for Windows Vista/7/8
Fixes file desciptor and zipos virtual memory sizes given that old versions of windows limit their user virtual memory space to 8tb.
Includes some changes from b69f3d2488 and 6f7d0cb1c3 in preparation for potentially using them on old windows and because it avoids duplicating addresses everywhere.
* Optimise windows version checking
Added GetNtMinorVersion() and IsAtleastWindows8p1() macros which get nt version info from the peb.
* Planned nsync memory region for old windows
Added nsync regon start and size macros that can switch to smaller values on old windows, just like previous fds and zipos change.