Export ol.ObjectEvent#key property
Update year in LICENSE
Add "img" option to ol.style.Icon
Merge pull request #2150 from probins/patch-1

Update year in LICENSE
Merge pull request #2112 from elemoine/iconload

Icon image loading related exports
Add getTileUrlFunction in ol.source.TileImage
Add getTileLoadFunction and setTileLoadFunction in ol.source.TileImage
Merge pull request #2133 from fredj/ol.ObjectEvent.key

Export ol.ObjectEvent#key property
Document Map.render() and Map.renderSync()
Add ol.FeatureOverlay tests
Merge pull request #2155 from probins/rendersync

Document Map.render() and Map.renderSync()
Merge pull request #2121 from oterral/utils_func_cache

Add getters and setters for TileUrlFunction and TileLoadFunction properties
Merge pull request #2156 from elemoine/featureoverlaytests

Add ol.FeatureOverlay tests