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 superg/fast-frames state dynamically-allocated (and indirect off
the com structure instead of embedded); this reduces the overhead when
not configured and reduces visibility of the contents

Hoist 802.11 encapsulation up into net80211:
o call ieee80211_encap in ieee80211_start so frames passed down to drivers
are already encapsulated
o remove ieee80211_encap calls in drivers
o fixup wi so it recreates the 802.3 head it requires from the 802.11
header contents
o move fast-frame aggregation from ath to net80211 (conditional on
IEEE80211_SUPPORT_SUPERG):
- aggregation is now done in ieee80211_start; it is enabled when the
packets/sec exceeds ieee80211_ffppsmin (net.wlan.ffppsmin) and frames
are held on a staging queue according to ieee80211_ffagemax
(net.wlan.ffagemax) to wait for a frame to combine with
- drivers must call back to age/flush the staging queue (ath does this
on tx done, at swba, and on rx according to the state of the tx queues
and/or the contents of the staging queue)
- remove fast-frame-related data structures from ath
- add ieee80211_ff_node_init and ieee80211_ff_node_cleanup to handle
per-node fast-frames state (we reuse 11n tx ampdu state)
o change ieee80211_encap calling convention to include an explicit vap
so frames coming through a WDS vap are recognized w/o setting M_WDS

With these changes any device able to tx/rx 3Kbyte+ frames can use fast-frames.

Reviewed by: thompsa, rpaulo, avatar, imp, sephe

o move tdma+superg protocol defs out of public view
o add #ifdef _KERNEL to superg+tdma include files so they can be used
by user code to get the protocol defs

Fix enough bits so that fast frames work again:
o include ath ie in beacon frames
o fix probe response check for including ath ie
o add ieee80211_add_athcap shorthand for ap-side ie additions

split Atheros SuperG support out into it's own file that's included only
with a new IEEE80211_SUPPORT_SUPERG option