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
Tested on an ESP32 with ST7789V display
SDA read is very slow on an ESP8266 (to be investigated)
Added new setup #define TFT_SDA_READ
Add new ESP32 and ESP8266 compatible in example/Generic folder to test
capture of TFT screen
Bodmer