Let bucket deletion be synchronous
Let bucket deletion be synchronous

Change-Id: I088d5fe2482efc4e8a6f39b3a6bc83faa8ba8f76
Reviewed-on: http://review.membase.org/5726
Tested-by: Trond Norbye <60edd2ef23891a753f231b0c6f161dc634079a93@gmail.com>
Reviewed-by: Chiyoung Seo <8b279095f11c26cc21045fda5a3e51debb005aa9@gmail.com>

couchbase/bucket_engine,membase/bucket_engine,couchbase/bucket_engine,membase/bucket_engine,membase/bucket_engine,membase/bucket_engine,couchbase/bucket_engine,couchbase/bucket_engine