CBD-708: Use possible hostname as node reference
CBD-708: Use possible hostname as node reference

If users prefer hostname as node reference, we can directly read
from var/lib/couchbase/ip.start file if it exists.

Change-Id: I76513d0f4c58505ca69dae5a069c7969777d0572
Reviewed-on: http://review.couchbase.org/23327
Reviewed-by: Steve Yen <ef850f73f7832052d3c6d9b5ddd3a1716d9a57f1@gmail.com>
Tested-by: Bin Cui <ed18693fff32c00e22495f4877a3b901bed09041@gmail.com>

membase/ns_server,t3rm1n4l/ns_server,ceejatec/ns_server,nimishzynga/ns_server,t3rm1n4l/ns_server,ceejatec/ns_server,pavel-blagodov/ns_server,daverigby/ns_server,vzasade/ns_server,vzasade/ns_server,t3rm1n4l/ns_server,pavel-blagodov/ns_server,ceejatec/ns_server,pavel-blagodov/ns_server,nimishzynga/ns_server,t3rm1n4l/ns_server,daverigby/ns_server,membase/ns_server,t3rm1n4l/ns_server,membase/ns_server,membase/ns_server,mschoch/ns_server,nimishzynga/ns_server,vzasade/ns_server,mschoch/ns_server,mschoch/ns_server,pavel-blagodov/ns_server,mschoch/ns_server,membase/ns_server,daverigby/ns_server,daverigby/ns_server,ceejatec/ns_server,nimishzynga/ns_server,mschoch/ns_server,mschoch/ns_server,vzasade/ns_server,ceejatec/ns_server,membase/ns_server,daverigby/ns_server,ceejatec/ns_server,nimishzynga/ns_server,nimishzynga/ns_server