Improved pdf usetex support: slanted and extended fonts

As of revision 6718, the usetex part of the pdf backend has support for
font effects (SlantFont and ExtendFont) specified in TeX's mapping
files. Together with the recent encoding fixes, this should make the
output visually identical to what pdftex would produce, assuming that
all fonts are Type-1 -- pdftex also supports the original type of TeX
fonts by encoding bitmaps as Type-3 fonts, but these should be rare in
modern TeX installations. The major missing feature is Type-1 font
subsetting to reduce output file sizes.

I would be especially interested in hearing reports from users of other
TeX distributions -- I use TeX Live 2008, but I have no idea how
distributions work on Windows.

I added the dviread and type1font modules in the backend API part of the
documentation tree, since these modules are likely only useful for
backend developers. This is my first foray into Sphinx documentation, so
please feel free to tell me if I got anything wrong.


Jouni K. Sepp�nen