Journaling status update.

[Matthew Dillon]

    Here's an update to the journaling work.

    I am making good progress on the mountctl user utility, system call,
    the journaling infrastructure, the data record format, and the actual
    act of journaling a piece of data as a transactional entity.  It is in
    fact possible to create, list, and delete a journaling stream (albeit
    a very truncated one since only test code is in the kernel right now 
    for portions of one or two VOP calls).

    This code is highly experimental so don't play with it unless you can
    suffer a crash :-).  It is NOT useful for doing anything real yet.
    However, it does allow me to exercise most of the code that I've 
    committed to date, and that is very important. 

    I consider this a significant milestone in the journaling work.

						-Matt