New serial protobuf transport approximately works and is backward

compatiable with the text debug output.

src/SerialConsole.h

@@ -0,0 +1,24 @@
+#pragma once
+
+#include "RedirectablePrint.h"
+#include "StreamAPI.h"
+/**
+ * Provides both debug printing and, if the client starts sending protobufs to us, switches to send/receive protobufs
+ * (and starts dropping debug printing - FIXME, eventually those prints should be encapsulated in protobufs).
+ */
+class SerialConsole : public StreamAPI, public RedirectablePrint
+{
+  public:
+    SerialConsole();
+
+    /// Do late init that can't happen at constructor time
+    virtual void init();
+
+    /**
+     * we override this to notice when we've received a protobuf over the serial stream.  Then we shunt off
+     * debug serial output.
+     */
+    virtual void handleToRadio(const uint8_t *buf, size_t len);
+};
+
+extern SerialConsole console;