Move the dcp repo into couchbaselabs

I also updated this repo with some of the latest code so that it
can be used in perfrunner.

Change-Id: I4d8d6f304a24eec1ba3b32fb4d6f870a80e78857
Reviewed-on: http://review.couchbase.org/43458
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: thomas anderson <thomas.couchbase@gmail.com>
Tested-by: thomas anderson <thomas.couchbase@gmail.com>