Small latex mods: Escapes, Headings, Equations

* remove console escapes
* use different heading levels
* allow explicit definition of latex environments
remove console escapes with sphinx templates
Convert ansi colors to latex markup
move Ansi related filters to ansi.py
Add missing color definintions to latex header
corrected small exporter bug
Update imports
Merge pull request #173 from jakobgager/latex_mods

Latex mods