font issues with eps and latex

I worked quite a bit on the TeX support in MPL this weekend. I think the code
is ready for wider testing, the changes are in CVS. Note there are a few new
options in .matplotlibrc:

1) font.latex.package allows you to select the latex fonts, but your selection
has to be a valid latex package.

2) text.tex.engine allows you to select tex or latex to handle the text

3) ps.usedistiller allows users to pass any ps/eps output through
ghostscript's distiller (this is a necessary step for creating eps output if
tex is handling the text). This will convert the fonts, shrink the file size,
and the resulting file should open more quickly. I have tested with
gnu-ghostscript-8.16. ghostscript-7.07 seems to have trouble getting the eps
bounding box right.

4) ps.distiller.res allows the dpi to be set. It defaults to 600, but I
personally have it set to 6000 to get the best on-screen results for
files embedded in tex and converted to pdf. (JDH- note this option was
briefly called text.tex.epsres)

I also silenced the tex, dvips and gs stdout messages. If you want to see all
the reports that they print, you can set verbose.level = debug-annoying

Changes are in CVS.