Added SD card storage for smooth fonts with ESP32
ESP32 will use PSRAM (if available and enabled) to hold smooth font
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Improve performance of ESP32 Sprite shared functions
Add basic ST7789 driver option
Latent bug fixes for pin mask
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
Four new examples have been added to show different methods of rendering
the anta-aliased fonts. A few minor bugs have been corrected associated
with the font rendering. drawNumber and drawFloat handle fixed width
mono fonts with no digit movement.
Bodmer