Added gunicorn dependency for deployment.
Added description field for RegisteredUser.
Added default value for description.
Migrated changes for RegisteredUser.
RegisteredUsers now refer to username only, not User objects.
Added migration for RegisteredUser change.
Updated all references to RegisteredUser to use its username field.
Added piwik api module requirement.
Added error pages.
Added error handling views.
Merge branch 'master' of git.gmu.edu:srct/go

Merging branch master.