Add its-phabricator-from-bugzilla f9fd2db7a62119ab9a6d1adfd3110b6e59b7a872

This plugin extracts the issue id using the "bugzilla" commentLink,
adds 2000 to the ids, and then takes actions on the resulting id on
phabricator. Using this plugin, changes that still use the bugzilla
bug numbers cause actions on the corresponding task in Phabricator.

For building this plugin, hooks-its commit
  3b8a1d4abaa6010faa0a18af8b7a00e68593f50c
got used.

Bug: T1327
Change-Id: I3e9f94c91c35f0eff87b52fc9cd4c1289f3cb20d