Add roles as nested routes to track (for the track organizer role)
Allow transition from to_accept to to_reject and backwards
Split Track#valid_dates validation to many independent ones
Show all the confirmed tracks in the conference's splashpage
Add comment in admin/Tracks#toggle_cfp_inclusion
Rewrite admin/TracksController#accept spec
Add feature spec for track requests
Change 'In' to 'Room' in Tracks#index
Rewrite Track#overlapping
Refactor code in ProposalsController
Fix typos
Allow track submitter to request specific dates
Redirect to Tracks#edit if a track doesn't have a room or start/end date
before accepting it
Don't allow the submitter or the track organizers to edit the request
after it has been accepted or confirmed
Restrict track selection in proposals and move track selection from
Proposals form to events helper
Mark cfp_active of the tracks table as not null and fill in true if nil
