Makefile.in: autodep stuff

dh.c: change format to binary from decimal string (without introducing
endianness problems)

ipaddr.c: implement the useful functionality from ipaddr.py

netlink.c: investigate why 'default' routes don't appear to work
(reported by JDA).
Test the 'allow_route' option properly.

random.c: test

rsa.c: check padding type, change format to binary from decimal string
(without introducing endianness problems)

site.c: the site_incoming() routing could be implemented much more
cleanly using a table. There's still quite a lot of redundancy in this
file. Abandon key exchanges when a bad packet is received. Modify
protocol to include version fields, as described in the NOTES
file. Implement keepalive mode. Make policy about when to initiate key
exchanges more configurable (how many NAKs / bad reverse-transforms
does it take to prompt a key exchange?)

slip.c: restart userv-ipif to cope with soft routes? Restart it if it
fails in use?
userv-ipif doesn't like the same bit of network to be specified
twice. Use the new functionality in ipaddr.c once it's done to prevent
this.
Work out why slip.c doesn't compile on Solaris-2.5.1

transform.c: separate the transforms into multiple parts, which can
then be combined in the configuration file.  Will allow the user to
plug in different block ciphers, invent an authenticity-only mode,
etc.

udp.c: actually send NAKs rather than just complaining.