-- Added AlreadySynced function.
-- When pulling a calendar from their respective places we will also check if the event is already present on our DBs (through their ICalendar IDs). This allows us to sync flawlessly and avoid duplicates across the board.
-- Re-factored the whole sync process
-- Moved the add functions from the CalendarManagers to the collection
-- Created a new collection called DBCollection to handle database read/write stuff.
-- Removed observableCollection from every piece of code
-- Fixed a few bugs that afflicted the sync.
-- Fixed other problems with sync
-- Forgot to add "description" when pushing an event to Google Calendar
-- Removed ObservableCollection references
-- Fixed unused using.
Merge branch 'feature/CalendarSync' into develop