HEADSUP: new ath and hal

[Sam Leffler]

I've mfc'd the v0.9.16.16 hal and related driver and rate control 
changes.  The new hal has support for the latest parts so once again all 
pci/cardbus cards should work (modulo the few cards based on the pre-11n 
mimo part).

If you hit issues please be sure to provide at least the following info:

1. card mac+phy revs; dmesg|grep ath typically provides that
2. ifconfig of the interface
3. steps to reproduce the problem if possible

There are still changes pending mfc but they should only affect ap mode. 
  I'm primarily interested in verifying station and adhoc mode operation.

	Sam