Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Make kttcp work in -stable (and -current)

- Removed kttcp_sosend() and kttcp_soreceive() in favor of using
sosend() / soreceive() with UIO_NOCOPY. The locking changes in the
socket layer make merging the kttcp_so* and the so* routines a real
pain. It was a lot easier to just use the integrated routines.

- Eliminated KTTCP_MAX_XMIT restrictions on send and receive sizes
because I encountered no problems with streams larger than MAX_INT.
MAX_INT bytes is only good for a few seconds at 4Gb/sec ;)

- Removed Giant from send / recv routines.

- Fixed character device protos, cdevsw init, etc, to work in 5.x /
6.x

Reviewed by: sam
MFC after: 1 week

Update for so_state->sb_state, SB_* flag renames.

Submitted by: rik

fixup include filenames; this stuff used to be in the kernel source tree

honor environment settings of SYSDIR and BINDIR

add in-kernel ttcp performance tool