Minor changes to the comments

src/ATC/ATCProjection.cxx

@@ -91,6 +91,7 @@ Point3D FGATCAlignedProjection::ConvertToLocal(Point3D pt) {
     return(Point3D(x,y,0.0));
 }
 
+// TODO - IMPLEMENT ME!!!
 Point3D FGATCAlignedProjection::ConvertFromLocal(Point3D pt) {
     return(Point3D(0,0,0));
 }

src/ATC/ground.cxx

@@ -457,6 +457,7 @@ Gate* FGGround::GetGateNode() {
 
 // WARNING - This is hardwired to my prototype logical network format
 // and will almost certainly change when Bernie's stuff comes on-line.
+// Returns NULL if it can't find a valid node.
 node* FGGround::GetThresholdNode(string rwyID) {
 	// For now go through all the nodes and parse their names
 	// Maybe in the future we'll map threshold nodes by ID