This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
in lots of unrelated junk from <net/if.h> and <net/if_ether.h>. These
functions still aren't prototyped anywhere (but should be in
<net/ethernet.h>---got that, Bill?).
