Update fixtures

Add competition fixture data and repository fixtures

Creates a competition and some teams (with proper groups) in the dev
database. Also creates repositories for those teams.
Catch connection errors when the webserver can't reach the arena

Resolves #60
Add an arena user to the dev data
Add default competition images
remove avatar from fixtures
Add Elo and TrueSkill ratings
Import GameScore
Add gevent for gunicorn
Remove dropdowns from navbar, link to competitions/docs pages directly
Fix icon for navbar expansion on mobile resolutions
Hide carousel on mobile resolutions
Add mobile.css for special mobile stylings
Merge branch 'mobile-update' into develop
Rework homepage to show open / running competitions for unauthenticated users
Only compute stats for complete games
Merge branch 'mobile-update' into develop
Add scripts to calculate competition data

They leverage [django-extensions](http://django-extensions.readthedocs.org/en/latest/runscript.html)
and can be used to calculate competition-related things
Check submission names more leniently

Fixes #55
Add caching for flat pages

This fixes #54
Add email address to registration script output