Mobile IPv6

[Robert Swindells <rjs%fdy2.co.uk@localhost>]

I have been doing some work on getting the Mobile IPv6 code from KAME
to build in -current.

The userland apps seem to do stuff but I think I am going to need some
help in thinking up how to debug it fully. It builds for rump but
I have not written any test scripts for it.

There are some additions to netipsec but I have not kept up with
whether it needs to be modified to match the recent locking changes
in this area.

I have put a snapshot of it on ftp.n.o in:

<http://ftp.netbsd.org/pub/NetBSD/misc/rjs/mip6-20170603.diff.bz2>
<http://ftp.netbsd.org/pub/NetBSD/misc/rjs/mip6-20170603.tar.bz2>

Robert Swindells