Merge pull request #2298 from probins/props

Document that options in layers and properties in features are set as object properties

src/ol/layer/tilelayer.js

@@ -17,6 +17,9 @@ ol.layer.TileProperty = {
  * @classdesc
  * For layer sources that provide pre-rendered, tiled images in grids that are
  * organized by zoom levels for specific resolutions.
+ * Note that any property set in the options is set as a {@link ol.Object}
+ * property on the layer object; for example, setting `title: 'My Title'` in the
+ * options means that `title` is observable, and has get/set accessors.
  *
  * @constructor
  * @extends {ol.layer.Layer}