Fix folder deletion; add support for folder rename (#2118439)

* Folder delete had a subtle error that could cause subsequent folder
  changes in the same sync to fail (using wrong end tag)
* Folder change (rename, move) wasn't implemented; this was added and
  tested.  The change is very straightforward and low risk.

Change-Id: Id69cee9b99e9a988a176a6525ba9a1615b741c44
1 file changed