matplotlib Code

Fixed image.aspect in matplotlib.template.

fix validation of ps.papersize : auto

Removed support for C0-C6 page sizes, they
cause problems with postscript viewers.

added link to usetex wiki

minor docstring fixes

updated comments in matplotlibrc.template concerning font.size

added a dvipng hack to allow mac users to get nice results with usetex

these changes should have gone in with the last commit regarding font.size

removed warning about ps.useafm breaking mathtext from matpltolibrc.template

Dropped support of tex engine in usetex, to focus on latex