This fix the conflict of having two functions called 'dsioctl()'.

FreeBSD/alpha.  The most significant item is to change the command
argument to ioctl functions from int to u_long.  This change brings us
inline with various other BSD versions.  Driver writers may like to
use (__FreeBSD_version == 300003) to detect this change.

The prototype FreeBSD/alpha machdep will follow in a couple of days
time.

This will not make any of object files that LINT create change; there
might be differences with INET disabled, but hardly anything compiled
before without INET anyway.  Now the 'obvious' things will give a
proper error if compiled without inet - ipx_ip, ipfw, tcp_debug.  The
only thing that _should_ work (but can't be made to compile reasonably
easily) is sppp :-(

This commit move struct arpcom from <netinet/if_ether.h> to
<net/if_arp.h>.

<sys/sockio.h> instead of <sys/ioctl.h> in network files.

ready for it yet.

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.

there were three possible different code paths through which we could
discard a packet (which, after all, is the entire function of this interface).

SNMP requirements. Update description of ifnet.if_lastchange in if.h
to indicate this.