add FIXMEs for Ellipse3D

src/orbits.h

@@ -30,6 +30,7 @@ struct OrbitalElements
 	double nu;		// (ν) true anomaly at T0
 };
 
+// FIXME: move to game.h
 struct Ellipse3D
 {
 	glm::vec3* vertices;
@@ -59,7 +60,7 @@ struct TwoBodySystem
 	GravBody body;
 	Satellite sat;
 	EllipseParameters ep;
-	Ellipse3D e3d;
+	Ellipse3D e3d; // FIXME: should be direct child of GameOrbit
 	OrbitalElements elements;
 
 	double epsilon;			// (ε) specific orbital energy, MJ/kg