Update reference lists and inline numberings automatically.

The easy part is getting the correct numbers from the InternalList
and generating the ordered list HTML. The tricky part is connecting
up the events to make sure the renumberings/list generations are
triggered when required.

InternalList can emit an update event on document transaction, which
triggers the renumbering/relisting if any references have been
added or deleted during that transaction.

ve.ce.MWReferenceListNode also listens to changes on the
InternalListNode (i.e. changes to the contents of the references)
and always triggers a rebuild.

Change-Id: I1b48ef5240e433c3b314259aa68cde13841ea98b
Merge "Update reference lists and inline numberings automatically."