Implemented EventBuilder
Fixed error handling in ICSParser - ducks exception, passes to caller
Merge branch 'evt_builder' into develop
Added threading for pulling calendars from google and parsing ICS files.

Merge results page will show parsing errors if there are any.
Added in CalendarBuiler
Fixed relevant calendar construction calls
Implemented strategy pattern for API management
Modified Merge/Pull Helper Java files to use new implementation
WILL NEED TO GENERALIZE FOR NEW APIs!!!
Removed unsused imports in ICSParser
Fixed Calendar Constr. Calls
Fixed calls to Calendar/Event Builders
Fixed some error handling
Fixed legacy code, and formatted files
Added in custom exceptions
Merge branch 'error_handler' into develop
Merge branch 'develop'