Bug 1108871 - handle option_collections in the job_exclusions

This fixes bug 1108871
The UI companion to https://github.com/mozilla/treeherder-service/pull/294

**STATE**
This feels solid to me, but I haven't had too much time to test it.  So if we want to push to production, then merge this to master for more testing on dev/stage, that's fine by me.

**Changes**
This changes the ``options`` values in the ``job_exclusions`` to be ``option_collections``.  When we save to the service, we add a field called ``option_collection_hashes`` which is used on the service.  But both the textual and the hashes are saved for convenience.

I had to add temporary handling for JSON field name change from ``options`` to ``option_collections`` to aid in migrating from the older versions of the exclusions.

When this is pushed, we need to go to every ``job_exclusion`` and ``exclusion_profile`` and re-save them to update the json.  ``job_exclusions`` first.