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.
Can now specify a colour that will not be plotted so some part of the
Sprite are "transparent" and the TFT backforund shows through. New
example added for demonstration.
Sprites (images) can now be created in RAM, written to with text and
graphics and rendered to screen quickly, this makes it easier to get
flicker frre screen updates.
ESP8266 can typically create up to a 160x128 sprite, and ESP32 about
200x200 pixels. 16 bit colour only at the moment, may soon implement 8
bit colour to reduce RAM.
Bodmer