Moon phases

This update introduces actual moon phases to the Zima Dashboard. I have implemented moon phase shapes in svg with two circles -- one for the moon and one for the mask, plus a blur filter to blur the edges. I used approximate formulas to figure out the corresponding circle radii and positions depending on the moon phase, such that I have a smooth transition between phases:

Here are the final results:

In future releases, I hope to add a subtle texture to the moon to make it look more realistic.