Fix use of dispose in ol.parser.KML
Fix use of dispose in ol.control tests
Fix use of dispose in ol.control.ZoomSlider tests
Fix use of dispose in ol.layer.Layer tests
Fix use of dispose in ol.layer.Vector tests
Fix use of dispose in ol.Map tests
Fix use of dispose in ol.renderer.webgl.ImageLayer tests
Remove unused ol.Object.prototype.changed
Change ol.source.WMTSOptions.projection type to ol.ProjectionLike

Same type as base class.
Merge pull request #645 from fredj/ol.object.changed

Remove unused ol.Object.prototype.changed
Merge pull request #647 from fredj/wmts.projection

Change ol.source.WMTSOptions.projection type to ol.ProjectionLike
Merge pull request #643 from twpayne/fix-dispose

Fix dispose
Add HTML drop support in kml example