this patch does a lot of things:
tested on macos and linux (debian)
adds --daemon for forking cjdroute into background
rewrites arguments parsing, and adds --config-file option
improves daemon mode
allow --log-file even when not in daemon mode
a good practise would be, to source out the privatekey (and probably publickey/ipv6) to an external configuration file, that should be enforced to 0600.
I'd really rather keep anything I can out of the main binary, my plan at the moment is to move cjdroute.c to cjdroute-internal.c and make cjdroute-internal have an api which is not guaranteed to be the same from day to day while a new python or perl script will take the place of cjdroute and provide the amenities to the user.
adds some brackets to comply cjdns code style
breaking long line to comply code style
newline to prevent merge conflict