Replaced image based TowerGit with HTML version
Add regex cheat sheet from Patterns App
Adding the restructuredText cheatsheet.

The restructuredText sheet is somewhat odd in that in it is best
displayed as formatted plain text, but could probably do with a 2-column
preview in a later iteration.

On its own branch for pull.
Merge pull request #11 from shalicke/pr_rst

Adding the restructuredText cheatsheet.
Merge pull request #10 from gilcreque/master

Replaced image based TowerGit with HTML version, added regex cheat sheet from Patterns App