AoE for 4.x

[Sam]

> I'm sure you mentionned this before, but why ar eyou not doing it against 
> -current first?
>
> We generally don't allow changes to 4.x untill they have settled a bit in 
> -current.  (or 5.x)

I decided to write a 4.x driver thinking it would a) be easier to port
forward than backward, and b) would give me experience in the old kernel
to understand why certain changes were made for the new.

[Thompson's Rule for First-Time Telescope Makers]
It is faster to make a four-inch mirror and then a six-inch mirror than
to make a six-inch mirror.

As for the single patch, I'll cook one up shortly.  I just figured it
would be more of a pain to look through.

Cheers,

Sam