Fix bug where circle angle property resets to 0 after first element when applying warp to multiple elements.

Instead of overwriting the circle.angle property with the calculated radian angle, the code should add a new property to keep the original angle property unaffected.
Not sure how it should be minified, so I'll leave that to someone else.
Merge pull request #1 from ericfreese/master

Fixed a bug where circle angle property resets to 0 after first element when applying warp to multiple elements