condensed some commits because they were small or already reversed

osu.Game/Graphics/UserInterface/BarGraph.cs

@@ -57,6 +57,7 @@ namespace osu.Game.Graphics.UserInterface
                             Length = bar.Value / (MaxValue ?? value.Max()),
                             Direction = Direction,
                         });
+                //I'm using ToList() here because Where() returns an Enumerable which can change it's elements afterwards
                 Remove(Children.Where((bar, index) => index >= value.Count()).ToList());
             }
         }