MB-10144: set hostname during node initialization

For unprovised cluster, we allow to set hostname other than
the default 127.0.0.1. No shortname is allowed though

Change-Id: Id0ee37c3ef4b920e08b38da484809e83d7a8af54
Reviewed-on: http://review.couchbase.org/35740
Reviewed-by: Bin Cui <bin.cui@gmail.com>
Tested-by: Bin Cui <bin.cui@gmail.com>