Privilege seperation in radns

Finally committed my changes for privelege seperation to the radns project. See the git repo.

The major change is a small and pretty stupid helper program called raresolv whose only job is to read single characters ("+" or "-") on a pipe and to call the resolvconf program to add or delete resolv.conf data.

I've had the code finished since late October but haven't got around to committing it until now.

I've just tested it on Debian Linux with the resolvconf program and on FreeBSD with openresolv.

I'm not ready for a new release just yet. I'm sure I did some mistakes. I also need to have a patch ready for the FreeBSD ports files.

Please pull and test!