Video submission

Sorry for the giant PR, most of it is updating requests and adding requests-oauthlib to vendor-local.

- Makes profile creation view actually completable.
- Adds video upload flow. The final frontend for this will be different, it's mostly repurposed from my prototype code and is reasonably close.
- Moves old videos to Video2012 model and makes a new Video2013 model for this year's contest, with an alias so that most code just uses Video. When 2014 rolls around we'll add an archive that uses the 2013 model and add a new model for 2014 (which will probably have different metadata requirements and thus a different table) and update the alias.