Show Aphlict connection status in notification menu

Summary:
Fixes T5373. Ref T5281. Several changes:

  - The `marshallExceptions` thing is useful if JS throws an exception when invoked from Flash, so set it. The resulting exceptions are a little odd (not escaped correctly, e.g.) but way better than nothing.
  - Put connection status in the notification menu.
  - When the connection fails, try to provide contextual help where we can.

Test Plan: {F169493}

Reviewers: chad, joshuaspence

Reviewed By: joshuaspence

Subscribers: epriestley

Maniphest Tasks: T5281, T5373

Differential Revision: https://secure.phabricator.com/D9700