Inconsistent behavior with polyStroke()

I noticed that `polyStroke()` has a quirk, where given 2 or 5 arguments, it draws unclosed polygons, i.e.:

```js
polyStroke([
// empty array as last point
[0,0], [64, 0], [64, 64], []
], 5)
```

When given 3 arguments however, it doesn't draw anything. I'm guessing this behavior appears because [this](https://github.com/script-8/script-8.github.io/blob/a60a494976db12e65cc21517b9637b05a0d858a8/src/iframe/src/frameBufferCanvasAPI/polyStroke.js#L18):
```js
Math.min.apply(
Math,
[[0,0], [1,1], []].map(p => p[0])
)
```

...would return `NaN`

Since drawing unclosed polylines has plenty of use-cases, perhaps this behaviour should be parametrized, and unified across the different drawing implementations?