Fix mappings
Switch remote example to Ajax proxy with api
Fix EventModel isRecurring check for null values
Read json request body, implement Ajax delete function
Remove lingering dependencies on the recurrence mappings

The calendar UI code should work even if no recurrence-related model mappings are defined
Implement add/update example API
Override mappings completely (instead of applying) to remove recurrence fields

Not needed, and cause an error on the back end when not all fields are mapped to columns
Fix app_id implementation for examples