made REST API serve ns_server version
made REST API serve ns_server version

Because menelaus and ns_server are long united

Change-Id: I89a74958a83649b483286e78e53ee285bc28bba0
Reviewed-on: http://review.membase.org/5252
Tested-by: Aliaksey Kandratsenka <340b8e09ca65cd3fc686427fcfed17e87eaf61e2@gmail.com>
Reviewed-by: Aliaksey Kandratsenka <340b8e09ca65cd3fc686427fcfed17e87eaf61e2@gmail.com>

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