Handle NoNode error from create Op in ZkOpList

Handle the case where NoNode exception is thrown because a path
is created or updated after it's deleted.  ZkOpList in that case
massages the internal data structures that store the Op objects
so that NoNode exception would not be thrown.

Change-Id: Ib29e2ac13ea4577580d99aa465e4fe7bde044d5e
Fixes: MNA-2
Merge "Handle NoNode error from create Op in ZkOpList" into staging/v2014.11