one_time_sequences in knock client

[addictedtocode]

I love knockd! The addition of the one_time_sequences feature changes port knocking from "security through obscurity" into a one-time pad.

It would be nice for the knock client to mirror the knockd behavior of reading/modifying a one_time_sequences file. I currently accomplish this with a perl script on the client machine which parses/modifies a local copy of the one_time_sequences file and then calls the knock client. But this is problematic on windows machines because perl is frequently not present.