Remove CPos.TopLeft and .BottomRight.
Add World parameter to Target.FromOrder.
Add World parameter to Target.FromCell.
Add World parameter to Util.BetweenCells.
Add World parameter to HeliFly and Fly.ToCell.
Replace CPos.CenterPosition -> world.CenterOfCell.
Remove WVec.ToCVec.
Replace WPos.ToCPos -> World.CellContaining.
Convert Viewport internals to world coordinates.
Convert viewport positioning to world coords.
Route screen size queries via Game.Renderer.
Convert Sound to world coordinates.
Convert ScreenShaker to world coords.
Convert Viewport.Scroll to world coordinates.
Remove PPos hacks from RadarWidget.
Introduce Viewport.MousePosition to simplify mouse queries.
Remove PPos from order generators.
Use SpriteRenderables for tile overlays.
Use SpriteRenderables for selection decorations.
Remove Sprite.DrawAt.