Connected as described at http://printrbot.com/shop/led-strip/

Based on patch by Kelly Anderson <kelly@xilka.com> at
http://www.xilka.com/printrbot/marlin/1.1.4/20170707/

Fixes #7250

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add test to Travis

Add support for the PCA9632 PWM color LED driver used on the Ultimaker 2 and Wanhao Duplicator 6.

The menu (commands / scripts) is configurable in `Configuration_adv.h`.

- Added conditionals.
- Changed script handling.
- Slimmed and working!
- Added Status message.
- Returning to lcd status screen now!
- Example Configs Updated.
- Cleanups by @thinkyhead

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make changes requested by reviewers

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add M43 test to Travis, fix EOL, remove trailing spaces

In the endstop testing section, add the "reverse" logic in addition to "normal" core handling.

In CoreXY/YZ/XZ steppers rotating the same direction gives X movement. Opposing directions produces Y movement.

In CoreYX/ZY/ZX this is reversed. Same = Y, Opposite = X.

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Fixes the issue where the Y endstop was being checked when moving in the X direction, etc.