client-interface-cleanup (#6)

Refactoring and code cleanup. Improved client command interface.

peer/mcwriter.go

@@ -15,16 +15,16 @@ func createLocalDiscoveryPacket(localIP byte, signingKey []byte) []byte {
 	}
 	buf := make([]byte, headerSize)
 	h.Marshal(buf)
-	out := make([]byte, headerSize+signOverhead)
+	out := make([]byte, headerSize+signingOverhead)
 	return sign.Sign(out[:0], buf, (*[64]byte)(signingKey))
 }
 
 func headerFromLocalDiscoveryPacket(pkt []byte) (h Header, ok bool) {
-	if len(pkt) != headerSize+signOverhead {
+	if len(pkt) != headerSize+signingOverhead {
 		return
 	}
 
-	h.Parse(pkt[signOverhead:])
+	h.Parse(pkt[signingOverhead:])
 	ok = true
 	return
 }