extend NOT_MY_VBUCKET responses to include configuration updates

To allow clients to more quickly update their understanding of the cluster topology, the NOT_MY_VBUCKET response should be extended to include the current known configuration. This updated configuration may not, in fact, be up to date with respect to the vbucket identified in the operation, but it should eventually be consistent with this change.

This configuration should include the fast forward map.

This is part of project CCCP, as covered at http://www.couchbase.com/wiki/display/couchbase/Cluster+Configuration+Carrier+Publication