Commented out unnecessary functions using too much memory
CC-5902: Linked Shows -> Replace content check assumes content of shows have the same number of tracks

Conflicts:
	airtime_mvc/application/services/SchedulerService.php
CC-5904: New linked show instances may get an old copy of the schedule
CC-5904: New linked show instances may get an old copy of the schedule

Better way of getting show stamp
Renamed variables
CC-5904: New linked show instances may get an old copy of the schedule

Change the way get the show stamp
Added criteria parameter to CcShow->getFutureInstanceIds so we can retrieve results from database instead of cache
Better way of getting the linked show schedule and moved that into its own function.
Store the ids of the new, created show instances so we can pass them to the
fillNewLinkedInstances function
Removed old comments
Added comments and removed some unused code
Clean up and simplifcation of linked show filling
Removed unused function.
Removed commented out code.
Renamed fillNewLinkedInstances to fillLinkedInstances.
Streamline show instance content if a show goes from unlinked to linked.
Removed unused code.
Changed linked show warning message in the edit show form.
Removed database test that confirms the is_linkable is set to false after a show is un-linked.
Since we removed this behaviour from Airtime, and a show can be linked and unlinked as many
times as the user wants, this test is deprecated.