Additional tests, documentation and example

src/ol/source/vectorsource.js

@@ -66,7 +66,9 @@ ol.source.VectorEventType = {
 
 /**
  * @classdesc
- * Provides a source of features for vector layers.
+ * Provides a source of features for vector layers. Vector features provided
+ * by this source are suitable for editing. See {@link ol.source.VectorTile} for
+ * vector data that is optimized for rendering.
  *
  * @constructor
  * @extends {ol.source.Source}

src/ol/source/vectortilesource.js

@@ -12,7 +12,13 @@ goog.require('ol.source.UrlTile');
 
 /**
  * @classdesc
- * Base class for sources providing images divided into a tile grid.
+ * Class for layer sources providing vector data divided into a tile grid, to be
+ * used with {@link ol.layer.VectorTile}. Although this source receives tiles
+ * with vector features from the server, it is not meant for feature editing.
+ * Features are optimized for rendering, their geometries are clipped at or near
+ * tile boundaries and simplified for a view resolution. See
+ * {@link ol.source.Vector} for vector sources that are suitable for feature
+ * editing.
  *
  * @constructor
  * @fires ol.source.TileEvent