Fix hashes in MW toDomElement functions

Hashes weren't using the new [ object, config ] set up so were
never matching the store. Also added a check to see if the
originalDomElements actually exists before trying to use them
(they may have been removed by a clone operation).

Change-Id: I886e369ced9a9d2e0e457ced9c21b2a7a8e55d58
Merge "Fix hashes in MW toDomElement functions"