Added CalendarObjectList
Abstracted Event and Commitment back to CalendarObject
Fixed tests for Events
Abstracted CommitmentList and EventList out to CalendarObjectList
Fixed bad month add commitments, added archaic heat map to year pane, and added missing import to year view.
Issue #47: Implemented commitmant pane filtering GUI, and implemented filtering for day view
Issue #47: Implemented commitment pane filtering for week view
Issue #47: Implemented commitment pane filtering on month view
Fixed #47: Implemented commitment pane filtering on year view
Fixed #60 setting the calendar appeared not to to modify it till another call was made on it, so changed to different set style
Fixed merge conflicts after abstracting Events and Commitments