convert Sphinx markdown documentation to restructuredtext

[rheone]

Markdown and Sphinx don't play as well together as we might like.
I've already made the conversion in Arcus, we should do the same in Gulliver. There is a bit of a learning curve but the juice should be worth the squeeze in the long run.

The m2r project will get us ~75% of the way there for the conversion preventing us from having to do a full conversion manually.

Beyond that Sphinx reStructuredText and Quick reStructuredText are the best references I've found thus far.