Corrected font 2 rendering issue #402
Corrected NULL pointer issue #400
Changed grave ` character (key for this character is left of numeral 1
key) to degree symbol in font 2
Change setup24 so DC pin is not D3
Added SD card storage for smooth fonts with ESP32
ESP32 will use PSRAM (if available and enabled) to hold smooth font
metrics
Improve performance of ESP32 Sprite shared functions
Add basic ST7789 driver option
Latent bug fixes for pin mask