Uninstall Conduit calls when uninstalling applications

Summary: Fixes T2698. When applications are installed, their Conduit calls should drop out. This will also let us land Releeph without exposing Conduit calls.

Test Plan:
  - Viewed Conduit console; uninstalled some applications and verified their calls dropped out.
  - Tried to make an uninstalled call; got an appropriate error.

Reviewers: edward, btrahan

Reviewed By: edward

CC: aran

Maniphest Tasks: T2698

Differential Revision: https://secure.phabricator.com/D5302

src/applications/paste/conduit/ConduitAPI_paste_Method.php

@@ -5,6 +5,11 @@
  */
 abstract class ConduitAPI_paste_Method extends ConduitAPIMethod {
 
+  public function getApplication() {
+    return PhabricatorApplication::getByClass(
+      'PhabricatorApplicationPaste');
+  }
+
   protected function buildPasteInfoDictionary(PhabricatorPaste $paste) {
     return array(
       'id'          => $paste->getID(),