locking.c: Added lock type to is_locked() and do_lock()

locking.c: Added lock type to is_locked() and do_lock()
           as the code in reply_lockingX wasn't taking account of
           the difference between read and write locks ! How did this
           ever work :-) !
reply.c:
server.c: Add lock type to is_locked() and do_lock().
util.c: Also added code from klausr@ITAP.Physik.Uni-Stuttgart.De
        to fix problem with log files growing too large if an
        smbd writes less than 100 debug messages.
Jeremy.