Add another todo

sources/PTYTab.m

@@ -151,6 +151,7 @@ static void SetAgainstGrainDim(BOOL isVertical, NSSize *dest, CGFloat value) {
     // If there is a flexible root view, this is set and is the tabview's view.
     // Otherwise it is nil.
+#warning TODO: I believe this prevents tmux windows from being transparent.
     SolidColorView *flexibleView_;
     // The root of a tree of split views whose leaves are SessionViews. The root is the view of the