LookupServer can now take two types of requests:
* L: Lookup
* R: Reverse lookup
The /bin/host program now does a reverse lookup if the input string is a
valid IPv4 address. :^)
Also run it across the whole tree to get everything using the One True Style.
We don't yet run this in an automated fashion as it's a little slow, but
there is a snippet to do so in makeall.sh.
