Add ns_bucket:get_buckets/1 which takes a config proplist.
Add ns_bucket:get_buckets/1 which takes a config proplist.

Change-Id: Ic20f620958b892dcb79fa7ce43a083ae5bd792ac
Reviewed-on: http://review.northscale.com/1746
Reviewed-by: Steve Yen <ef850f73f7832052d3c6d9b5ddd3a1716d9a57f1@gmail.com>
Tested-by: Steve Yen <ef850f73f7832052d3c6d9b5ddd3a1716d9a57f1@gmail.com>

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