Split ... * `_circleHandlesSourceId` into `_circleCenterHandleSourceId`/`_circleRadiusHandlesSourceId` * `_circleHandlesStrokeId` into `_circleCenterHandleStrokeId`/`_getRadiusHandlesStrokeLayer` * `_getHandlesGeoJSON` into `_getCenterHandleGeoJSON`/`_getRadiusHandlesGeoJSON` * `_getHandlesMapSource` into `_getCenterHandleMapSource`/`_getRadiusHandlesMapSource` * `_getCircleHandlesStrokeLayer` into `_getCenterHandleStrokeLayer`/`_getRadiusHandlesStrokeLayer`
Split ... * `_circleHandlesSourceId` into `_circleCenterHandleSourceId`/`_circleRadiusHandlesSourceId` * `_circleHandlesStrokeId` into `_circleCenterHandleStrokeId`/`_getRadiusHandlesStrokeLayer` * `_getHandlesGeoJSON` into `_getCenterHandleGeoJSON`/`_getRadiusHandlesGeoJSON` * `_getHandlesMapSource` into `_getCenterHandleMapSource`/`_getRadiusHandlesMapSource` * `_getCircleHandlesStrokeLayer` into `_getCenterHandleStrokeLayer`/`_getRadiusHandlesStrokeLayer`

And animate separately. Fixes #55.

mblomdahl/mapbox-gl-circle,mblomdahl/mapbox-gl-circle,mblomdahl/mapbox-gl-circle