Proof of concept

@jcasimir This branch is WIP but it's a proof of concept.  There is a failing test that is the full integration test from full input file to full output file.

###Still to be done

* Add in headers for slides that don't have their own (after a code break)
* fix a bug where a new slide is being added for a comment in a code block ('#')
* there are a bunch of extra new lines that need to be removed
* paragraphs starting with punctuation ('`', for example) are not being removed.  They should be
* Make the {% terminal %} blocks get their own slides

I'll work on the above issues tomorrow a bit more but any feedback would be great.