mrdoob/three.js — pull request #3839 by em (2013-09-05 04:30:18+00:00)
Title: Make ellipses work with negative angles

Follow up to #3833

This adds support for negative angles.

Compared to canvas:

https://cloudup.com/cvxpvRFW6EG

```
ctx.arc(100,100, 100, 0, Math.PI*2);

ctx.arc(100,100,20, -9, -5);
ctx.arc(200,100,20, 3, 4);
ctx.arc(300,100,20, -3, 2);
ctx.arc(400,100,20, 3, -2);
ctx.arc(500,100,20, 0, 5);

ctx.arc(100,100,50, 1, 2, true);
ctx.arc(200,100,50, 3, 4, true);
ctx.arc(300,100,50, -3, 2, true);
ctx.arc(400,100,50, 3, -3, true);
ctx.arc(500,100,50, 3, 8, true);
ctx.lineTo(500, 0);
```