kthreads->kproc and back to kthread.. next patch

Here is the link to the next patch.

this introduces (back) the kthread_create (etc) calls but now they
make threads..
It's still in the testing stage..
I'd certainly appreciate feedback.
Especially as some of the locking and stuff has changed since I first wrote 
this and tested it over 2 years ago.

One possibility.. changing kthread_create() to kthread_new()
so that any people who are using the old kthread_create() don't get the new
one by mistake....


after this is committed, I will start changing over some of the callers of kproc_create,
one at a time....


     http://people.freebsd.org/~julian/kthread.diff


it may also be worth adding some help for people to make a new kproc,
and populate it with a number of kthreads.

for instance it would be aesthetically pleasing to have a single idle process,
and have all the idle threads be part of that single process.

 Similarly, might things like the syncer or other processes ever 
benefit from having multiple threads?
Anyhow that's another discussion.