Switch to IPv4 zeroconf, add test framework with discovery test, fix serial enumeration

lib/client/types.go

@@ -9,10 +9,19 @@ type RequestInfo struct{}
 type ResponseInfo struct {
 	BoardID      [8]byte
 	MAC          [6]byte
-	LinkLocal    [16]byte
+	IP           [4]byte
 	FirmwareName string
 }
 
+type RequestTest struct {
+	Name string
+}
+
+type ResponseTest struct {
+	Pass     bool
+	Messages []string
+}
+
 type DeviceError struct {
 	Code    uint32
 	Message string
@@ -35,4 +44,6 @@ func init() {
 	msgpack.RegisterExt(3, (*ResponsePICOBOOT)(nil))
 	msgpack.RegisterExt(4, (*RequestInfo)(nil))
 	msgpack.RegisterExt(5, (*ResponseInfo)(nil))
+	msgpack.RegisterExt(127, (*RequestTest)(nil))
+	msgpack.RegisterExt(126, (*ResponseTest)(nil))
 }