Fixed off-by-one errors for Call and mess parsing
Fixed recvline so it returns -1 on closed socket

Had to replace the recv(.., MSG_DONTWAIT) with a select(..); recv(.., 0)
since there was no way to distinguish between a partial line and a
closed socket.

And guess what... PuTTy sends lines like HELP\r\n as two freaking TCP
packets. TCP("HELP") TCP("\r\n") Because that makes sense.