teams: Plug-in names to the UI

* Update the views to display team.name instead of team.slug.
* Add UI field to support defining name at team creation time.
* Update model to take name from provided options, defaulting to
  slug if not provided.

Fixes #1012.
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I didn't yet test this with an actual running server so I wouldn't merge this without actually testing it live :-)

How have people been running test servers where you have to login? Do you have to run it on Heroku or something so that it can have an actual oauth callback?