Better document which events are fired

The map does not fire ol.render.Event#render. Change events are
now only listed for classes that fire them, and a description
about when they are fired is added.

src/ol/map.js

@@ -158,7 +158,8 @@ ol.MapProperty = {
  * @param {olx.MapOptions} options Map options.
  * @fires ol.MapBrowserEvent
  * @fires ol.MapEvent
- * @fires ol.render.Event
+ * @fires ol.render.Event#postcompose
+ * @fires ol.render.Event#precompose
  * @todo api
  */
 ol.Map = function(options) {