Several schedules in the backend && routes changed

- Introduce plural resources for Schedule in routes.rb
- Introduce #index and #create actions for ScheduleController
- Make it possible to set a schedule as selected_schedule

app/views/admin/schedule/_day_tab.html.haml

@@ -0,0 +1,13 @@
+.row
+  - @rooms.each do |room|
+    .col-md-2.col-xs-6
+      .room-name
+        = room.name
+      - (9*4..18*4).each do |slot|
+        - hour = slot / 4
+        - time = (15 * (slot % 4) == 0) ? '00' : 15 * (slot % 4)
+        .schedule-room-slot{ id: "schedule-room-#{room.guid}-#{hour}-#{time}", |
+                             "room-guid" => room.guid, |
+                             hour: "#{hour}:#{time}", |
+                             date: date}
+          = "#{hour}:#{time}"