KnockSequenceManager is used to store knock sequences
in a file and read them from a file - currently just
stores the vector.
Sequence is still hardcoded at this point - GUI will
provide editing facilities.
Main: improved the way it gets the local IP address,
including ignoring local addresses starting with a zero
- which I've been having a problem with since
installing a webcam - Windows set up a dummy network
interface with IP 0.1.4.10 and the old code was picking
that up as the local IP.