Better color pattern editor, for easier LED A/B control

[todbot]

@mrfoto says: "Yeah, the pattern palette should be much improved. Maybe make a palette just a list of patterns and a separate screen which is just pattern maker/editor with two timelines - one for led 1, one for led 2. I imagine it sort of like a movie editor. So it would be very easy to see what is/will be going on, easy to adjust fade-ins and most importantly - work on per led basis. Does that make sense?"