Dev/jpsnyder/led/frame

Added the function frame() to LED API. This is an undocumented function to allow the user to subsitute the framebuffer with their own framebuffer given as a numpy array. Useful for speeding up stuff like the camera project.

- Also added a fill argument to rectangle.
Can you revert this back?  Did you have an issue with this code?

I require it from my Mac because I don't have python3.