Alpstein/route-me — pull request #69 by incanus (2012-06-04 17:04:19+00:00)
Title: better fix for RMCircle path changes & artifacts

This is an improvement on the [#65](https://github.com/Alpstein/route-me/pull/65) `RMCircle` patch from before.

The previous solution of swapping out the `CAShapeLayer` solves the problem of sizing up or down without clipping artifacts, but behaves weirdly when the map view is zoomed in or out.

Before: http://dl.dropbox.com/u/575564/path_before.mov

This patch instead reverts the `CAShapeLayer` swap and instead explicitly adds an animation to changes to the `path` properly of it. Per the class docs:

> Unlike most animatable properties, path (as with all `CGPathRef` animatable properties) does not support implicit animation.

So this adds the animation if we exist inside of a `CATransaction` block with `duration`, matching its duration, for cases where we are animating zoom.

After: http://dl.dropbox.com/u/575564/path_after.mov