Allow the PullLocal daemon to actually hibernate

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

src/applications/diffusion/editor/DiffusionURIEditor.php

@@ -507,6 +507,10 @@ final class DiffusionURIEditor
         ->synchronizeWorkingCopyAfterHostingChange();
     }
 
+    $repository->writeStatusMessage(
+      PhabricatorRepositoryStatusMessage::TYPE_NEEDS_UPDATE,
+      null);
+
     return $xactions;
   }