matplotlib Code

fix call to numpy.get_include/numpy.get_numpy_include

get_numpy_include deprecated, changed to get_include

remove libm for vs builds

attempt to improve tk finding abilities - ADS

added axisbelow to rc

Added code to allow compilation with visual studio for win32

fixed a setup bug for 64 bit systems

Added _isnan extension module to test for nan with Numeric

Added _subprocess.c from Python upstream and hopefully
enabled building (without breaking) on Windows, although
not tested. - ADS