Updates from the blink1 site

Whilst I was looking at how this gem works I noticed that [blink1](https://github.com/todbot/blink1/tree/master/commandline) had been updated.  So I've copied over the changes.  Which seem to be:

*   a new method fade_to_rgbn.  As far as I can tell it's for a new (mk2) blink(1) where you may control individual leds
*   a few bug fixes
*   tidying up code, including whitespace