giscannermodule.c: Updates for Windows

giscannermodule.c: Updates for Windows

-Incorporate and extend Dieter's patch regarding possible different CRTs
 used in Windows Python (msvcrt71.dll for Python 2.5, msvcrt90.dll for
 Python 2.6- 3.2, and msvcrt100.dll for Python 3.3+) vs. the CRT used to
 build g-i (msvcrt.dll for MinGW/WinDDK, msvcrt90.dll for stock MSVC 2008
 and msvcrt100.dll for stock MSVC 2010)
-Avoid C99ism for NEW_CLASS as we are having an array without a
 pre-determined length.  There might be better ways to get around this
 though.

https://bugzilla.gnome.org/show_bug.cgi?id=681820