Flatbuffer, Forwarder

- Flatbuffer now only sends data if priority registration was successful
- Forwarder no longer needs to worry about registering the priority

libsrc/flatbufserver/hyperion_reply.fbs

@@ -3,6 +3,7 @@ namespace hyperionnet;
 table Reply {
   error:string;
   video:int = -1;
+  registered:int = -1;
 }
 
 root_type Reply;