Summary: Closes T7937, Calendar events should be supported in global search.
Test Plan: Search for part of calendar event title in global search, event should be in search results.
Reviewers: #blessed_reviewers, epriestley
Reviewed By: #blessed_reviewers, epriestley
Subscribers: Korvin, epriestley
Maniphest Tasks: T7937
Differential Revision: https://secure.phabricator.com/D12636
