Cool new stuff, clean-up & more!

Hey Steven! I wanted to collaborate to your really cool API, so therefore I built upon it (for my own little project). Since I added quite some cool stuff I thought I might share.

List of edits:
- Added Button.getX() and Button.getY().
- Added Button.isBlinking() and Button.isLit()
- Added Button.toggle();
- new Color class, moved static colors in there.
- Added Color.getColor(red, green)
- Added Color.getX(note) and Color.getY(note)
- Moved Button.mapToLaunchpad inside launchpad class
  -> now called Launchpad.getX(note) and Launchpad.getY(note)
- Added optional midi_output for the launchpad constructor
- Added semicolons where necessary.
- Documentation for all
- White-space cleanup

Regards,
- Jerom