DIS-192: Indexing improvements, handling sublocations, other fixes

[Abhyastamita]

• Renamed Native Events to Aspen Events everywhere to avoid future confusion
• Added indexing for facets, including up to three custom facets
• Fixed some display and link issues with the calendar template for Aspen Events
• Added code for indexer so that it can either do a full index or only index changed events
• Added handling to indexer for deleted events and event instances. Changed deleting events/event instances so that they are not removed from the database but the Deleted field is set to 1 so that the deleted list can be queried when indexing.
• Added the ability to choose a sublocation when creating an event.
  • Still need to add ability to change the sublocation for an event instance.
• Fixed permission restrictions for events, event instances, and the event admin menu.
• Added restrictions to prevent deleting event fields, field sets, and event types if they are in use.
  • Still need to set up ability to archive event types, which right now doesn't do anything.
• Updated release notes.