LionFastLcd

Keeps a RAM shadow of the display and pushes only the cells that actually changed, coalescing runs of consecutive cells into a single setCursor() to cut I2C traffic. Implements Arduino Print, so use print()/println() as usual. Supports stacked/overlay screens via Clone()/Activate()/Deactivate() with a z-order. The class is non-copyable and objects are created only through CreateMain()/Clone() (they register in a static list and are meant to live for the program's lifetime); call CreateMain() once before any Clone()/Activate(). The shadow buffer is cols*rows bytes. Depends on LionArray and marcoschwartz/LiquidCrystal_I2C. Optional scrolling of over-long lines is ESP8266-only and OFF by default: build with -DFLCD_LONG_MESSAGES and add leva/LionTask. ESP8266 + AVR.