Summary: Ref T7950, Refactor Calendar Search, and implement Projects on events
Test Plan: Verify that all queries in Calendar search still work, and that events can now have associated Projects that you can search by in Calendar Search.
Reviewers: epriestley, #blessed_reviewers
Reviewed By: epriestley, #blessed_reviewers
Subscribers: epriestley, Korvin
Maniphest Tasks: T7950
Differential Revision: https://secure.phabricator.com/D13393
