Adds support for common-anode tri-color LEDs

From my experimentation so far, LEDs from Adafruit are common-anode, and need all of the high-low inputs swapped.  This PR also cleans up some formatting and doesn't re-instantiate the j5 led variables in each interval, in order to stop the LED from flickering.

This is just a quick-and-dirty fix that redefines on() and off().  I think the real fix should probably be to johnny 5, so that things like pulse() and fade() work properly.