rewrote parts of Msg.pm and client.c so that the messages no longer use

rewrote parts of Msg.pm and client.c so that the messages no longer use
a length word at the front of each one. They are simply strings of characters
separated by a \n. No binary characters are allowed (they are encoded as %nn)
a la HTTP. This hopefully cures Arnold's problem and also make it more
secure anyway. It also paves the way for the ax25/ip multicast client.