Add Math Support/Abstract

Rationale
---------
I have often wanted to have a tool that allows complicated layouts but is still
easy to use. This is exactly what Scribus does. However, for scientific
papers it lacks one main capability: Formulas. So I want to add this feature
as my Summer of Code project. Interest in this enhancement is expressed
by many people in the bug tracker [1][2] and by Debian users [3] and it's 
also listed as a desirable feature in the Scribus roadmap [4].


Overview
--------
The goal of this project is to add easy-to-use math support to Scribus.
As the task of writing a complete math typesetter is too large for SOC, a 
different approach is used. It is inspired by the Quark XPress(tm) plugin 
MATHSETTER [5]:

o Let the user enter LaTeX source either directly or in a more user-friendly
  way via a graphical editor.
o Apply a LaTeX template to this, so the user only has to type the formula
  and not a whole TeX document.
o Run LaTeX on this source.
o Display LaTeX's output in a frame while still keeping the 
  (LaTeX-)formula as a property, so the whole thing stays editable.

Use cases 
---------

o Scientific posters 
  It is very hard (if not impossible) to create good-looking posters
  with LaTeX but it's easy to add formulas to LaTeX documents. On the other
  hand it's very easy to create good posters with Scribus, but a complicated
  process is necessary to add just a single formula. The ability to use LaTeX 
  for typesetting the formula and then post-processing it in Scribus (easily
  possible, after all it's just a vector graphic from Scribus' point of view)
  would greatly simplify this. 

o Math/Physics teachers 
  At school, I've seen a lot of teachers who created their tests with Microsoft
  Word and relied on its formula editor or even on basic text formatting
  (sub-/superscript). They added any "complicated" math symbols (vectors,
  integrals, etc.) by hand to the printout. Obviously, the full power of
  LaTeX is something they are unwilling to learn (and it is probably not 
  required for them). So I believe they would be happy to have a WYSIWYG
  tool that supports embedded formulas.

Deliverables
------------
o Math support
o Patches to Scribus to integrate an external UI editor
o Python bindings