Add loadObject() methods to PhabricatorObjectMailReceiver subclasses

Summary: This doesn't do anything, but touches a bunch of files so I split it out to reduce the size of the next diff. Basically, make `MailReceiver` classes responsible for loading their application objects. Ref T1205.

Test Plan: Inspection / next diff / code is not reached.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T1205

Differential Revision: https://secure.phabricator.com/D5941

src/applications/macro/mail/PhabricatorMacroMailReceiver.php

@@ -11,4 +11,14 @@ final class PhabricatorMacroMailReceiver extends PhabricatorObjectMailReceiver {
     return 'MCRO[1-9]\d*';
   }
 
+
+  protected function loadObject($pattern, PhabricatorUser $viewer) {
+    $id = (int)substr($pattern, 4);
+
+    return id(new PhabricatorMacroQuery())
+      ->setViewer($viewer)
+      ->withIDs(array($id))
+      ->executeOne();
+  }
+
 }