Changes to support NEOPIXEL LED strips
- Support for different NEOPIXEL as defined in Adafruit_NeoPixel.h
- ability to setup startup brightness
- ability to define sequential/non-sequential transition of color change during heating-up
- additional parameter to M150 P<brightness>

- Original CR-10
- MKS Mini Display

Forgot to update examples configurations. Done now

Ideally, it should be calculated based on Z steps per unit so that each
babystep corresponds to around 0.025mm. Smaller than this is largely
insignificant for typical layer heights.

* Add MAX7219_DEBUG to Travis CI testing

* Tweak config and use standard pin naming for MAX7219_DEBUG

* MAX7219: Apply coding standards, use macros, etc.

* Make code work...

* Add Max7219 LED Matrix Debug Support

The Max7219 8x8 LED Matrix's are very helpful for debugging new code.
And for that matter, just trying to maximize printer settings without
causing stuttering.

The displays are very inexpensive (under $2.00 with shipping) and
provide a lot of help when trying to debug complicated code.

* Try to keep Makefile up to date.