Get rid of stability annotations and document stability with api

This change adds a stability value to the api annotation, with
'experimental' as default value.

enum, typedef and event annotations are never exportable, but
api annotations are needed there to make them appear in the
docs.

Nested typedefs are no longer inlined recursively, because the
resulting tables get too wide with the current template.

src/ol/mapbrowserevent.js

@@ -40,19 +40,16 @@ ol.MapBrowserEvent = function(type, map, browserEvent, opt_frameState) {
   /**
    * @const
    * @type {Event}
-   * @todo stability experimental
    */
   this.originalEvent = browserEvent.getBrowserEvent();
 
   /**
    * @type {ol.Coordinate}
-   * @todo stability experimental
    */
   this.coordinate = map.getEventCoordinate(this.originalEvent);
 
   /**
    * @type {ol.Pixel}
-   * @todo stability experimental
    */
   this.pixel = map.getEventPixel(this.originalEvent);
 
@@ -64,7 +61,6 @@ goog.inherits(ol.MapBrowserEvent, ol.MapEvent);
  * Prevents the default browser action.
  * @see https://developer.mozilla.org/en-US/docs/Web/API/event.preventDefault
  * @override
- * @todo stability experimental
  * @todo api
  */
 ol.MapBrowserEvent.prototype.preventDefault = function() {
@@ -77,7 +73,6 @@ ol.MapBrowserEvent.prototype.preventDefault = function() {
  * Prevents further propagation of the current event.
  * @see https://developer.mozilla.org/en-US/docs/Web/API/event.stopPropagation
  * @override
- * @todo stability experimental
  * @todo api
  */
 ol.MapBrowserEvent.prototype.stopPropagation = function() {
@@ -471,25 +466,25 @@ ol.MapBrowserEvent.EventType = {
    * A true single click with no dragging and no double click. Note that this
    * event is delayed by 250 ms to ensure that it is not a double click.
    * @event ol.MapBrowserEvent#singleclick
-   * @todo stability experimental
+   * @todo api
    */
   SINGLECLICK: 'singleclick',
   /**
    * A click with no dragging. A double click will fire two of this.
    * @event ol.MapBrowserEvent#click
-   * @todo stability experimental
+   * @todo api
    */
   CLICK: goog.events.EventType.CLICK,
   /**
    * A true double click, with no dragging.
    * @event ol.MapBrowserEvent#dblclick
-   * @todo stability experimental
+   * @todo api
    */
   DBLCLICK: goog.events.EventType.DBLCLICK,
   /**
    * Triggered when a pointer is dragged.
    * @event ol.MapBrowserEvent#pointerdrag
-   * @todo stability experimental
+   * @todo api
    */
   POINTERDRAG: 'pointerdrag',
 
@@ -497,7 +492,7 @@ ol.MapBrowserEvent.EventType = {
   /**
    * Triggered when a pointer is moved.
    * @event ol.MapBrowserEvent#pointermove
-   * @todo stability experimental
+   * @todo api
    */
   POINTERMOVE: 'pointermove',
   POINTERDOWN: 'pointerdown',