Feature suggestion: Transparent or colorized juggler body

[noslowerdna]

Occasionally there are patterns where the forearm briefly passes behind the body for a frame or few, leaving a 'blip' in the animation as it disappears then reappears. So I often find myself adjusting the Y coordinate forward for certain throw or catch events to avoid this.

I would suggest an option to render the juggler's body as transparent (or maybe any color, now that transparent is supported, with the default remaining white).

[jkboyce]

The idea here is allowing a user-defined color for painting the body (and head) of the juggler. (Specifically the fill color, not the outline color.) There are two ways this could be added:

1. As a setting in Animation Preferences. There is currently a hidejugglers setting that hides all painting for a juggler. There could be a related animation setting to define color on a per-juggler basis, potentially subsuming hidejugglers.
2. As a pattern-setting variable, which would then be represented in the JML version of the pattern. The natural thing would be to add an optional JML tag akin to <prop type="ball" mod="color=green"/> but for juggler definitions. The <setup> tag format would be adjusted to make reference to these juggler definitions, the same way it is done for props.

The first approach would be easier to implement, but the second approach would be more general and allow for future changes to juggler drawing style.