WIP 1.2 move routing into plugin

src/plugins/RoutingPlugin.h

@@ -0,0 +1,31 @@
+#pragma once
+#include "ProtobufPlugin.h"
+
+/**
+ * Routing plugin for router control messages
+ */
+class RoutingPlugin : public ProtobufPlugin<Routing>
+{
+  public:
+    /** Constructor
+     * name is for debugging output
+     */
+    RoutingPlugin();
+
+  protected:
+    friend class Router;
+
+    /** Called to handle a particular incoming message
+
+    @return true if you've guaranteed you've handled this message and no other handlers should be considered for it
+    */
+    virtual bool handleReceivedProtobuf(const MeshPacket &mp, const Routing &p);
+
+    /** Messages can be received that have the want_response bit set.  If set, this callback will be invoked
+     * so that subclasses can (optionally) send a response back to the original sender.  */
+    virtual MeshPacket *allocReply(); 
+
+    void sendAckNak(Routing_Error err, NodeNum to, PacketId idFrom);
+};
+
+extern RoutingPlugin *routingPlugin;