wait for orchestrator presense for key operations. MB-4214 MB-4559
wait for orchestrator presense for key operations. MB-4214 MB-4559

Due to mb_master sometimes needing few seconds to detect mastership,
we poll for readyness of orchestrator before doing key orchestrator
calls.

Change-Id: Icd267ba4551e833d8484dfdd71ec9c664660916a
Reviewed-on: http://review.couchbase.org/11808
Tested-by: Aliaksey Artamonau <3c875bcfb3adf2a65b2ae7686ca921e6c9433147@gmail.com>
Reviewed-by: Aliaksey Kandratsenka <340b8e09ca65cd3fc686427fcfed17e87eaf61e2@gmail.com>

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