Conpherence - make the calendar have a better calendar looking view up top

Summary: Ref T2400 and M14.

Test Plan: had a few conpherences with various status set amongst participants; views were sensical.

Reviewers: epriestley, chad

Reviewed By: chad

CC: aran, Korvin

Maniphest Tasks: T2400

Differential Revision: https://secure.phabricator.com/D5541