Merge pull request #2204 from probins/dragbox

Correct/improve dragbox docs

src/ol/interaction/interactiondefaults.js

@@ -32,6 +32,9 @@ goog.require('ol.interaction.PinchZoom');
  * * {@link ol.interaction.MouseWheelZoom}
  * * {@link ol.interaction.DragZoom}
  *
+ * Note that DragZoom renders a box as a vector polygon, so this interaction
+ * should be excluded if you want a build with no vector support.
+ *
  * @param {olx.interaction.DefaultsOptions=} opt_options Defaults options.
  * @return {ol.Collection} A collection of interactions to be used with
  * the ol.Map constructor's interactions option.