Fix issue where the draw.changed event payload returned all features instead of just the changed features.
Fix issue where the draw.changed event payload returned all features instead of just the changed features.

kiRach/mapbox-gl-draw,kiRach/mapbox-gl-draw,mapbox/gl-draw,mapbox/gl-draw,mapbox/mapbox-gl-draw,drewbo/mapbox-gl-draw,mapbox/mapbox-gl-draw,drewbo/mapbox-gl-draw