v1.6 -> v1.7

Argh, I still got the PPP fixes wrong. As distributed v1.6 would only
work correctly with PPP interfaces if you also got my Linux kernel
patches for PPP.

I updated the command-line help output to reflect the addition of some
options.

I added the printing of T/TCP or TAO options. See W. Richard Stevens'
"TCP/IP Illustrated, volume 3" for more info. Although I made these
changes independently of those by mr. Stevens, they look surprisingly
similar. I only checked out his WWW page after I had done them.
