This fixes the bug that bitmap changes do not cause screen updates
and optimizes the refresh when the bitmap is simply shown on the
screen. If the bitmap is used in tiles, then changing it will
cause all TileGrids using it to do a full refresh.
Fixes#1981
Different operations to the display tree have different costs. Be
aware of these costs when optimizing your code.
* Changing tiles indices in a TileGrid will update an area
covering them all.
* Changing a palette will refresh every object that references it.
* Moving a TileGrid will update both where it was and where it moved to.
* Adding something to a Group will refresh each individual area it
covers.
* Removing things from a Group will refresh one area that covers all
previous locations. (Not separate areas like add.)
* Setting a new top level Group will refresh the entire display.
Only TileGrid moves are optimized for overlap. All other overlaps
cause sending of duplicate pixels.
This also adds flip_x, flip_y and transpose_xy to TileGrid. They
change the direction of the pixels but not the location.
Fixes#1169. Fixes#1705. Fixes#1923.
This brings it inline with Group. Also fixes#1613
This also includes a number of fixes for where a method is called
through a subclass. We now correctly get the native object.
Fixes#1567
Lastly, this adds subscript support to TileGrid for changing tile
indices. Similar to Bitmap, it accepts ints or 2-tuples.
* Fix Hallowing.
* Fix builds without displayio.
* Fix y bounds that appears as untrollable row of pixels.
* Add scrolling to TileGrid.
* Remove Sprite to save space. TileGrid is a drop in replacement.
