display is slow for some reason.
According to the data sheet, the display sets an internal variable, BF, to 0 when it is ready for another command, and sets it to 1 when the display is busy. So, now the code waits for the display to set BF to 0 prior to sending any commands to it.
Used the version from the adafruit, since it now has the dimmer modification in it. Conflicts: SPI_VFD.cpp SPI_VFD.h
Added Brightness control and fixed bugs/inconsistencies in SPI_VFD library
(thanks jpbot for noticing).
(1=25%,2=50%,3=75%,4=100%; default is 100%).