[CMake] NMake target with 2.4.2

[James Mansion]

I fired up cmakesetup to create nmake files and it whinged that it can't
find gcc.exe.

Which is fair enough because my msys shell prompts have that but my VStudio
ones don't.

Surely if someone has nmake then they have a Microfoft compiler, and if they
have gcc then they are more likely to use the msys or cygwin target or have
their own win32 port of gnumake.

Is it intentional to look for non-ms tools with an ms-specific make?