I got the SVG backend to work properly. The PS backend seems
> to be very tightly integrated with the current
> implementation of the Fonts classes so I haven't realy
> digged into it yet.
> This patch only adds four new files for converting TeX/Type1
> <-> Unicode, and the modified mathtext.py file.
A couple of comments
* can we put all the dictionaries and data into a single file
(_mathtext_data). I would rather not have a proliferation of
support modules for mathtext
* do we really need dictionaries for tex2uni and uni2tex. Would it
not be better to define tex2uni and then do
uni2tex = dict([(v,k) for k,v in tex2uni.items()])