CRDT fixes.

This fixes the NPE that was being hit when returnbody=false on updates,
updates to the latest riak_pb which also removes the "add" operation
for maps.
Fixed failing CRDT set test
Fix CRDT set iTest

fixes iTestDtUpdateOperation.testCrdtSet
Merge pull request #448 from basho/gh438-NPE-in-crdts

CRDT fixes.