speed enhancements

1: I fixed all the broken example code.
2: I added SPI and PWM hacks in the code that one can enable if they have done the hardware modifications.
3: I did several speed enhancements.
4: Reformatted the code. Embedding a tab character will look horrible if you print this code out, worse, everybody has a different tab length. Best-practice says use spaces instead, and just FYI tabs are 8 spaces... The Arduino IDE uses a broken 4 space tab.

Details:
The SPI hack simply uses the regular SPI on the ICSP connector, and is much faster than bit-banging. Never mind the 9bit transmission, it already handles that too.
The PWM hack allows the backlight to be controlled via PWM from the AVR.

You can add/modify/ditch the README.md changes if you wish.