Document r319390, cxgbetool(8) addition.

Document r319390, cxgbetool(8) addition.
Document r298427, truss(1) '-H' flag.
Document r304017, ptrace(2) threaded process debugging improvements.
Document r306533, devctl(8) 'clear driver' added.
Document r309560, cxgbe(4) T6 support.
Document r309447, cxgbe(4) VF support for T4/T5 cards.
Document r309560, cxgbe(4) VF support for T6 cards.
Document r308154, cxgbe(4) additional virtual interface support.
Document r306520, PCI passthrough/bhyve improvements.
Document r306472, PCI passthrough/bhyve improvements.

Submitted by:	jhb
Sponsored by:	The FreeBSD Foundation

git-svn-id: svn://svn.freebsd.org/base/stable/10@319606 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f