don't let Mock{Server,Session} threads delay process exit
don't let Mock{Server,Session} threads delay process exit

This seems to be working a bit like java, where you need to mark
threads as daemon if you don't want your process to wait for their
completion.

Change-Id: I4efaf955f0298c0627d4b52f30170475d69c4fbe
Reviewed-on: http://review.northscale.com/1321
Reviewed-by: Steve Yen <ef850f73f7832052d3c6d9b5ddd3a1716d9a57f1@gmail.com>
Tested-by: Steve Yen <ef850f73f7832052d3c6d9b5ddd3a1716d9a57f1@gmail.com>

couchbase/moxi,zbase/moxi,couchbase/moxi,steveyen/moxi,couchbase/moxi,couchbase/moxi,membase/moxi,steveyen/moxi,membase/moxi,steveyen/moxi,membase/moxi,zbase/moxi,zbase/moxi,zbase/moxi,zbase/moxi,membase/moxi,membase/moxi,steveyen/moxi,membase/moxi,couchbase/moxi,steveyen/moxi,couchbase/moxi