ath changes: please test

There's a new hal and patch for the ath driver available for test:

http://people.freebsd.org/~sam/ath_hal-20051212.tgz
http://people.freebsd.org/~sam/ath.patch

The patch is against current.  I just committed a bunch of net80211 
changes that are required so be sure your system is up to date before 
applying the ath patch.

The changes include:
o updates for the sample rate control algorithm (from madwifi)
o use a private taskq thread
o improved sta mode beacon miss handling
o mcast frames sent at fixed rate (settable with ifconfig)
o adhoc mode beacon timer fixups
o packet capture now includes tsf and calibrated signal data
o dfs wait-for-clear-channel handling (for ap mode)

This code has been in test for a while and should be fine to use but I 
will not commit it until I get feedback.  Please send me mail directly. 
especially if you see regressions from the current code in cvs or from 
the 0.9.16.3 hal snapshot I've had out for several months.

All this stuff will eventually make it to RELENG_6 but not for a bit.

	Sam