Fixed mouse position when canvas is scaled using World#scaleResolution;
Removed World#getOffsets() (use World#xOffset and World#yOffset instead);
Removed App.Utils.percentToPixels() because it was unused and not very useful;
Made App.Utils.positionOverCanvas() more reliable;
Mouse.Coords now has worldX() and worldY() methods to get the mouse position in the world;
Note that Mouse.coords changed to Mouse.Coords (upper-case C)