support multiple directives in rgb file

[Human]

Currently, only a single directive is expected to be in the rgb file. This works great if the color changes infrequently, but there's no feedback about what state the lights are actually in, so it's impossible to gain precise control for things like blinking or rapid cycling of colors.

Extend the rgb file format to support multiple lines of directives. As long as the rgb file does not change, Hugh will continue cycling through the directives.

Current example (100% blue):

0, 0, 255

Future example (100% blue, followed by 100% red):
0, 0, 255
255, 0, 0

[Human]

Can be implemented independently of #1 and #3.