Update README with new protocol information

Change-Id: I1d1c6dd3d181e7264d486beefbc195c86c989a89
Reviewed-on: http://review.couchbase.org/27824
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>
Tested-by: Trond Norbye <trond.norbye@gmail.com>