CBIDXT-213 UPR Negotiation and Data Rollback

Change-Id: I9565610e49123d5cd979b6a6befd4d62a17ad26f
Reviewed-on: http://review.couchbase.org/42350
Reviewed-by: John Liang <johliang00@gmail.com>
Reviewed-by: Deepkaran Salooja <deepkaran.couchbase@gmail.com>
Tested-by: Deepkaran Salooja <deepkaran.couchbase@gmail.com>