Port the rwsnoop DTrace Toolkit script to FreeBSD.
Remove dependency on the Korn Shell.
Remove Zones in favor of Jails.
Remove support (for now) for filename printing.
Remove debugging options from the rwsnoop script.
The accept filter code is not specific to the FreeBSD IPv4 network stack,
so it really should not be under "optional inet". The fact that uipc_accf.c
lives under kern/ lends some weight to making it a "standard" file.

Moving kern/uipc_accf.c from "optional inet" to "standard" eliminates the
need for #ifdef INET in kern/uipc_socket.c.

Also, this meant the net.inet.accf.unloadable sysctl needed to move, as
net.inet does not exist without networking compiled in (as it lives in
netinet/in_proto.c.) The new sysctl has been named net.accf.unloadable.

In order to support existing accept filter sysctls, the net.inet.accf node
has been added netinet/in_proto.c.

Submitted by:	Steve Kiernan <stevek@juniper.net>
Obtained from:	Juniper Networks, Inc.