Implement track scheduling

Add track association to schedule
Show schedules in admin sidebar to track organizers
Allow track organizers to manage the schedules of their tracks
Don't allow self-organized track events to be dragged or unscheduled in
a conference schedule
Make scheduled events of self-organized tracks appear semitransparent in
conference schedules
Make the rooms of confirmed self_organized tracks appear semitransparent
and don't allow events to be scheduled to it in the conference schedules
during the dates of its track
Create admin/SchedulesController#new action
Add a button in admin/Schedules#index to create schedules for tracks
Add self_organized scope to Track
Modify Schedules#show to handle track schedules and show a unified
schedule
Allow track organizers to create new schedules for their tracks
Correctly identify scheduled and unscheduled events in Schedules#events
Fix Event#room and Event#time for when the event is scheduled in a track
schedule
Modify Program#selected_event_schedules to include the event_schedules
of selected track schedules
Modify Track#revoke_role_and_cleanup to destroy the track's schedules
and revert its events' state to new
Add tabs for conference and track schedules in admin/Schedules#index
Add button to Create/Show a tracks schedule in Tracks#index and #show
Fix concurrent_events in application_helper because of changes in
Program#selected_event_schedules
Do not take into account cfp_active in Event#valid_track
Modify EventsController#get_tracks accordingly
Enforce cfp_active of track to be enabled for proposals in
ProposalsController#create and #update
Add support for multiple schedules per track
Add selected_schedule_id to Track
Load EventSchedules of selected track schedules for conference schedules
in admin/SchedulesController#show
Modify SchedulesController#show to take into account only the selected
track schedules
Create Event#selected_schedule_id and use it in Event#scheduled? and
Event#time
Validate that an EventSchedule for an event of a self-organized track
belongs to one of the track's schedules
Add 'Manage' button in Tracks#index, #show that sends you to the admin
side of things
Add admin/TracksController#update_selected_schedule to update the
selected_schedule_id of tracks

app/models/track.rb

@@ -7,7 +7,9 @@ class Track < ActiveRecord::Base
   belongs_to :program
   belongs_to :submitter, class_name: 'User'
   belongs_to :room
+  belongs_to :selected_schedule, class_name: 'Schedule'
   has_many :events, dependent: :nullify
+  has_many :schedules
 
   has_paper_trail ignore: [:updated_at], meta: { conference_id: :conference_id }
 
@@ -38,6 +40,7 @@ class Track < ActiveRecord::Base
   scope :accepted, -> { where(state: 'accepted') }
   scope :confirmed, -> { where(state: 'confirmed') }
   scope :cfp_active, -> { where(cfp_active: true) }
+  scope :self_organized, -> { where.not(submitter: nil) }
 
   state_machine initial: :pending do
     state :new
@@ -102,7 +105,10 @@ class Track < ActiveRecord::Base
     submitter.add_role 'track_organizer', self
   end
 
-  # Revokes the track organizer role and removes the track from events that have it set
+  ##
+  # Revokes the track organizer role, destroys the track's schedule, removes the
+  # track from events that have it set and reverts their state to new
+  #
   def revoke_role_and_cleanup
     role = Role.find_by(name: 'track_organizer', resource: self)
 
@@ -112,8 +118,14 @@ class Track < ActiveRecord::Base
       end
     end
 
+    self.selected_schedule_id = nil
+    save!
+
+    schedules.each(&:destroy!)
+
     events.each do |event|
       event.track = nil
+      event.state = 'new'
       event.save!
     end
   end