r20092: added a locking benchmark that should be good for benchmarking

r20092: added a locking benchmark that should be good for benchmarking
communitcation in a CIFS clustered server. It tries to keep the
connections full by setting up the next lock as each lock is done.

The locking pattern is similar to the local filesystem ping pong test
in junkcode, forcing a communication between nodes on each request
(This used to be commit d57b9fb29860bd03cfa970bcc52ef45d17775638)