Support additional events for HipChat plugin

In newer versions, Jenkins HipChat plugin supports notifications for the
following events:

  notify-success
  notify-aborted
  notify-not-built
  notify-unstable
  notify-failure
  notify-back-to-normal

This commit adds support for these events in JJB. Also, introduces a
unit test for hipchat module and converts doc example generation to
literalinclude.

Change-Id: I3e09b4f2b41db58eb22ada89a633516e319a95bc
Merge "Support additional events for HipChat plugin"