Bug 2761: Don't EVER send the flush command.
Bug 2761: Don't EVER send the flush command.

This gets propagated over tap connections and deletes *all* data on
any node that has replicas of vbuckets on the node where the command
is sent.

Change-Id: Iaab0947a7954f5e0a04d09a100d29ce28c554763
Reviewed-on: http://review.northscale.com/3205
Reviewed-by: Steve Yen <ef850f73f7832052d3c6d9b5ddd3a1716d9a57f1@gmail.com>
Tested-by: Steve Yen <ef850f73f7832052d3c6d9b5ddd3a1716d9a57f1@gmail.com>

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