Fixed up some specs for user_sessions_controller (some still need work)
Refactored all FactoryGirl factories to correctly use sequences and
correctly instantiate models. Refactored & DRY'd up tons of specs.

Refactored Race.registerable? and all friends to respect the
difference between finalized and non-finalized registrations

Enabled registrations to be created even when a race is full (waiting
list)
Improving reg views, fixed and more specs, days_to_close
Added Race.waitlist_count, race display cleanup

Found bugs:
- team panel should display registration.race.name
- need to move registrations resource out from under races
- team reg info is looking jumbled when viewing teams#index