Nmakefile: Set the /SUBSYSTEM for 5.01 (win32), or 5.02 (x64) to allow running on Windows XP. In x86-32-vista mode, don't set it.
Nmakefile: Set the /SUBSYSTEM for 5.01 (win32), or 5.02 (x64) to allow
running on Windows XP. In x86-32-vista mode, don't set it.

real information:
https://software.intel.com/en-us/articles/linking-applications-using-visual-studio-2012-to-run-on-windows-xp

Fixes #1257.

bjourne/factor,bpollack/factor,mrjbq7/factor,bpollack/factor,mrjbq7/factor,bjourne/factor,dch/factor,AlexIljin/factor,nicolas-p/factor,slavapestov/factor,bjourne/factor,bpollack/factor,nicolas-p/factor,bjourne/factor,tgunr/factor,nicolas-p/factor,factor/factor,bpollack/factor,slavapestov/factor,bjourne/factor,tgunr/factor,tgunr/factor,nicolas-p/factor,factor/factor,dch/factor,AlexIljin/factor,mrjbq7/factor,AlexIljin/factor,slavapestov/factor,AlexIljin/factor,AlexIljin/factor,factor/factor,dch/factor,AlexIljin/factor,slavapestov/factor,slavapestov/factor,dch/factor,bjourne/factor,nicolas-p/factor,tgunr/factor,tgunr/factor,slavapestov/factor,dch/factor,factor/factor,factor/factor,mrjbq7/factor,slavapestov/factor,bjourne/factor,nicolas-p/factor,dch/factor,bpollack/factor,nicolas-p/factor,tgunr/factor,mrjbq7/factor,mrjbq7/factor,factor/factor,bpollack/factor,bpollack/factor,AlexIljin/factor