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)

o) Check that no overrun or CRC errors were encountered in receiving a
packet. Linux, OpenBSD and our iwn(4) all do this. It also results in
a huge performance improvement (and the rejection of a fair number of
apparently-bad packets on receive) on my hardware.
o) Like the wpi(4) driver in OpenBSD, and like our iwn(4), also drop runt
packets.
o) Don't bother doing IFQ_POLL and then IFQ_DRV_DEQUEUE, just do
IFQ_DRV_DEQUEUE outright. This is more similar to how OpenBSD and our
iwn(4) work.

Reviewed by: sam

Update wpi(4) with stability fixes
- remove second taskqueue
- busdma 16k alignment workaround
- use busdma instead of external mbuf storage on Rx
- locking fixes
- net80211 state change fixes
- improve scanning reliability
- improve radio hw switch interaction
- consolidate callouts

Parts obtained from: benjsc, sam
Tested by: many

Handle missed beacons correctly

Approved by: mlaier (comentor)

Initial Import of wpi driver based on p4 changeset 128641.

This import includes:
o wpi Wireless driver for the Intel 3945 Wireless Lan Controller (802.11abg) (sys/dev/wpi)
o Intel firmware revision 2.14.4 & associated LICENSE (sys/dev/contrib/wpi, sys/contrib/dev/wpi/LICENSE)
o wpifw Firmware driver (sys/modules/wpifw)

Approved by: mlaier, sam (co-mentors)