Fix GoogleMaps example view max zoom levels
Expose the map renderer type to the public API

In the case  where the map decides itself which renderer to use. It can
be convenient for the developer to have knowledge of the choice made.
Rename ol.RendererHint to ol.RendererType
Provide ol.RendererType structure through ol.renderer.Map

It was previously in ol.Map, but it could not be provided because
of circular dependencies.
Rename Map.DEFAULT_RENDER_HINTS to Map.DEFAULT_RENDERER_TYPES
Add docs link to loadingstrategy
Enhance and improve the accessibility example.

Changes to improve the accessibility example:

 - remove the `accesskey` attributes. Use of the `accesskey` is generally not recommended as it tends to cause conflicts with AT software and user settings.
 - Change the scripted "Go to map" accesskey to a regular skiplink.
 - Use script to inject the buttons below the map, if the map were to fail for lack of javascript support the buttons should not be there either. These should be buttons (and not hyperlinks) because they provide an action not a navigation.
 - Update the docs.
 - Add an empty `alt` attribute to the logo since it is strictly decorative (this should probably be done sitewide - which IMO is out of scope for this PR)
Make getFeatureById method exportable
Add interface for map events so properties can be disambiguated
Make map property of ol.MapEvent exportable
Make frameState property of ol.MapEvent exportable
Merge pull request #2161 from tschaub/exports

Map event and vector source exports.
Add offset and offsetOrigin in ol.style.Icon
Add parsing of gx:x, gx:y, gx:w and gx:h tags in KML format
Make sure WFS format writing works correctly in IE9+
Merge pull request #2165 from bartvde/ie-xml-write

Make sure WFS format writing works correctly in IE9+ (r=@tschaub)
Restore control’s keyboard navigation
Add ol.style.Icon tests for getAnchor and getOrigin
Add ol.format.KML test for complex IconStyle
Merge pull request #2164 from oterral/sprite

Allow the use of sprite image in KML