Added the filters to `ScheduleController`.

CHANGES
* Added the constructor function to `ScheduleController` containing all
the necessary filters and school session retrieval functionality.
nil result message for course search view.

CHANGES
* The search view now returns a `nil result` message when a user's query
returns zero results.
Added School Session selection for Schedules

CHANGES
* Added a school session selection box into the Schedules view.
Created Schedule Generation view.

NEW
* Created the view for the "Generate a Schedule" interface.