Clone template dom elements being sent to converter

The dom elements in the IV store are used for rendering, so if they
are sent by reference to the converter they get re-attached, causing
all templates to disappear from the page whenever you press 'review
and save'.

Fix is to run it through ve.copyArray, which clones all the nodes.

Change-Id: I1b03351a28ac82e0fdb7e94e761cf65d6548e501
Merge "Clone template dom elements being sent to converter"