add the heading to the dynamics to allow a position prediction

BaseTypes.proto

@@ -22,6 +22,7 @@ message Waypoint {
 
 message Dynamics {
     int32 groundSpeed   = 1; // given in knots
-    int32 altitude      = 2; // given in feet
-    int32 verticalSpeed = 3; // given in feet/min
+    int32 heading       = 2; // reported heading
+    int32 altitude      = 3; // given in feet
+    int32 verticalSpeed = 4; // given in feet/min
 }