(More) wireless hackery

So instead of doing what I should be doing, I did some more wifi hackery.

The short summary version (all 802.11g 2.4ghz testing):

• AR5416 TX is still unhappy and unpredictable. It's also like that with ath9k. AR5416 RX is perfectly fine.
• AR9160 TX/RX is fine.
• AR9220 (Ubiquiti SR71-12 and Ubiquiti-SR71-15) TX/RX is now fine.
• AR9280 closed and open-loop TX is fine, RX is also fine.
• AR9285 TX/RX is fine and stable now.

I'll now go and test out 5GHz AP/STA modes with the above (where appropriate) and see how they behave. I hope they'll be just as stable now.

Bernard has been making inroads into fleshing out the missing parts of the net80211 802.11n support. Many thanks to him for taking the time to dissect the 802.11n spec, the Linux 802.11 stack and spend time with some APs determining what they're doing.