Convert Our Simplates To Jinja2

Hey there, this pull request converts our existing Tornado simplates to Jinja2 simplates.

The changes in the actual simplates are the following:

- Quote all file include names
- Convert all end tags to endif, endfor, endblock, etc
- Convert u to unicode() (this was done because unicoded strings are available inside Jinja
- Convert escape() to string|e 

Before this is pulled in we need to fix the following things:

- [ ] Look for any nonescaped, user supplied strings
- [ ] Fix negotiated simplates
- [ ] Push an update to aspen-jinja2-renderer
- [ ] Include the required libraries in vendor so we don't have to download them.
- [ ] Go over python code additions with an expert (@whit537 or @zwn maybe?) 


Thanks!