Update toy build.
Update to add ns_server from my repo forked from Couchbase.
Add vbucket_rebalance from my repo forked from Kang.

Change-Id: Iee69c4f2f860eed1a38c7a110129845f073a1f4f
Reviewed-on: http://review.couchbase.org/23642
Reviewed-by: Sriram Melkote <siri@couchbase.com>
Tested-by: Sriram Melkote <siri@couchbase.com>