querycmd: Discover indexer ports from cluster address

querycmd will now accept -server=cluster_address
Indexer admin port and scan port will be discovered
automatically by using cluster endpoint.

Change-Id: I654c25a47653a335f77c972700e42000329c838a
Reviewed-on: http://review.couchbase.org/44091
Reviewed-by: Deepkaran Salooja <deepkaran.couchbase@gmail.com>
Reviewed-by: Sarath Lakshman <sarath@couchbase.com>
Tested-by: Sarath Lakshman <sarath@couchbase.com>