CBIDXT-272: projector to detect localhost node.

- projector needs to detect the server name of the local-node that is found
  in ns-server's server-list.
- added `projector.colocate` parameter in system-config.
- moved tools/{datapath,multibuckets} to SinglePartition.

Change-Id: I00653222c453838aa52ddf682de214ea06c0f0ba
Reviewed-on: http://review.couchbase.org/43297
Reviewed-by: Deepkaran Salooja <deepkaran.couchbase@gmail.com>
Reviewed-by: Pratap Chakravarthy <prataprc@couchbase.com>
Tested-by: Pratap Chakravarthy <prataprc@couchbase.com>