This commit was manufactured to restore the state of the 2.0-RELEASE image.
Releases prior to 5.3-RELEASE are omitting the secure/ and crypto/ subdirs.

IN_RMX.  (Eventually this will be standard, but I just wrote the code today
and don't want to break anyone.)

Fixed somebody's idea of a joke - about the first half of the lines in
in_proto.c were spaced over by one space.

multicast routing to be implemented as an LKM.  (There's still a bit of
work to do in this area.)

to something more recent than the ancient 1.2 release contained in
4.4.  This code has the following advantages as compared to
previous versions (culled from the README file for the SunOS release):

- True multicast delivery
- Configurable rate-limiting of forwarded multicast traffic on each
  physical interface or tunnel, using a token-bucket limiter.
- Simplistic classification of packets for prioritized dropping.
- Administrative scoping of multicast address ranges.
- Faster detection of hosts leaving groups.
- Support for multicast traceroute (code not yet available).
- Support for RSVP, the Resource Reservation Protocol.

What still needs to be done:

- The multicast forwarder needs testing.
- The multicast routing daemon needs to be ported.
- Network interface drivers need to have the `#ifdef MULTICAST' goop ripped
  out of them.
- The IGMP code should probably be bogon-tested.

Some notes about the porting process:

In some cases, the Berkeley people decided to incorporate functionality from
later releases of the multicast code, but then had to do things differently.
As a result, if you look at Deering's patches, and then look at
our code, it is not always obvious whether the patch even applies.  Let
the reader beware.

I ran ip_mroute.c through several passes of `unifdef' to get rid of
useless grot, and to permanently enable the RSVP support, which we will
include as standard.

Ported by: 	Garrett Wollman
Submitted by:	Steve Deering and Ajit Thyagarajan (among others)

Reviewed by:	Rodney W. Grimes
Submitted by:	John Dyson and David Greenman