GSoC progress report

Hi Martin,

I removed sc_ec/sc_if from ath(4) and made a few other minor changes.
Some criticism of my work on ath(4) would be very helpful (probably in
particular code I disabled, some of which I was unsure about -- though
it seems like the driver functions fine).

One other question -- very early on sc_mtx (as it is in FreeBSD) was
removed from ath(4) in NetBSD.  (TX buffers and queues still have
mutexes on them.  A few other mutexes were added to the softc in
FreeBSD in the meantime.)  Should that be added back, or should spl*
simply stay for now?  How does it relate to MPSAFE?

I also began with athn(4) on another branch (can come back to it).

Jeandre