r3034: - fixed a bug in message dispatch, when the dispatch function called messagin...

r3034:  - fixed a bug in message dispatch, when the dispatch function called messaging_deregister()

 - added a pvfs_lock_close_pending() hook to remove pending locks on file close

 - fixed the private ptr argument to messaging_deregister() in pvfs_wait

 - fixed a bug in continuing lock requests after a lock that is blocking a pending lock is removed

 - removed bogus brl_unlock() call in lock continue

 - corrected error code for LOCKING_ANDX_CHANGE_LOCKTYPE

 - expanded the lock cancel test suite to test lock cancel by unlock and by close

 - added a testsuite for LOCKING_ANDX_CHANGE_LOCKTYPE
(This used to be commit 5ef80f034d4aa4dd6810532c63ad041bfc019cb8)