Summary: Ref T12298. The PullLocal daemon has had hibernation code for a little while, but it never actually activated because we don't sleep for more than 15 seconds in any case. Add a maximum sleep instead and use that to control the longest sleep we'll do for hibernation purposes. Also, when a repository or repository URI is edited, write a NEEDS_UPDATE event into the message table to make sure the daemons de-hibernate. Test Plan: Used `bin/phd debug pull`, saw the daemon actually hibernate instead of just sleeping for 15 seconds. Reviewers: chad Reviewed By: chad Maniphest Tasks: T12298 Differential Revision: https://secure.phabricator.com/D17635