sockstat tcp/udp switches

[Josh Carroll]

> Can we have something that doesn't need one option letter for each
> protocol, protocol family or socket type, please? :)

I'd be willing to modify it to take a -P argument with one of:

tcp
udp
tcp,udp
udp,tcp

If the consensus is to add -P, I'd be happy to make the changes. I
assume without -P we'd want to show both, so perhaps udp,tcp and
tcp,udp aren't necessary.

Thanks,
Josh