- Added shortcuts to TScreenBuffer to speed up the InsertionSort
- Renamed TScreenBuffer.Store to TScreenBuffer.Insert
- Added TScreenBuffer.Add to append to the list
- Added TScreenBuffer.Sort to sort the list using MergeSort
- Changed TLandscape.FillDrawList to just append to the list and sort afterwards
- Added screen buffer invalidation on TfrmMain.OnLandscapeChanged