ADAFRUIT GP9002 VFD Driver supporting grayscale display, requires GFX-Library Note no "invert" function, also fixed timing issue in "begin"

Dependencies:   bitreversetable256

Dependents:   GP9002af_gray

Fork of Adafruit-GP9002-Graphic-VFD-Library by Oliver Broad

Adafruit_GP9002.cpp/shortlog/shortlog@e760d4cfabe4: not found in manifest