Speed up Sprite rotation on an ESP32
Update utf8 serial decoder to handle illegal format strings
Remove need for D0_USED_FOR_xx (issue #271)
Clean up setup files
Correct various comment typos
Sprites can be rendered rotated with defined pivot points, 3 new
examples have been added "Rotated_Sprite_1/2/3".
The FLASH bitmap example has been moved to the Generic examples folder.
Boundary checks have been added to pushImage()
A new scrolling and wrapping in a Sprite example has been added.