[iOS] Fix bug with OC Deletes

Address bad merge from Dev to Offline with version changes being lost
Update OC Delete test case to be more robust
Fix bug is deserialization of table operation’s with item
Merge pull request #330 from phvannor/offline

[iOS] Fix bug with OC Deletes
[offline][managed][client] CancelAndDiscard and CancelAndUpdate methods should throw if the associated operation is collapsed in another thread
[client][managed][offline] Improved handling for 409 conflicts