CBIDXT-140: Send Snapshot messages downstream.
CBIDXT-140: Send Snapshot messages downstream.

Change-Id: Ic2b8b24f15f6cdd072641fb4f8770d4109f934b6
Reviewed-on: http://review.couchbase.org/40408
Reviewed-by: John Liang <e1e1383402f9cdee00b021b8a653005f3061b036@gmail.com>
Reviewed-by: Pratap Chakravarthy <3f7aa3c5f732447448ccfcd013fd9591a9825870@couchbase.com>
Tested-by: Pratap Chakravarthy <3f7aa3c5f732447448ccfcd013fd9591a9825870@couchbase.com>

t3rm1n4l/indexing,t3rm1n4l/indexing,jchris/indexing,jchris/indexing,jchris/indexing,jchris/indexing