Some changes to the models.

* `Assoc`s now have fields for
    * views
    * upvotes
    * downvotes
* `Video`s now have a description field
* Users can now (in theory) specify a preferred resolution, default is 480p
Merge branch 'master' of github.com:pharpend/lambdatube

Conflicts:
	Model.hs
	config/models