Instead of "icltx" and "iclrx", use thread names with prefix from upper
layer, so that one can see which side of the stack the threads are for.

Sponsored by:	The FreeBSD Foundation
Use atomic ops instead of mutexes where appropriate.

Submitted by:	mav@
Sponsored by:	The FreeBSD Foundation
Get rid of the "autoscaling", instead just set socket buffer sizes
in the usual way.  The only thing the old code did was making things
less predictable.

Sponsored by:	The FreeBSD Foundation
Enable a KASSERT.

Sponsored by:	The FreeBSD Foundation