Blocker Description
It seems we forget to redirect some base classes to its counterparts in api, because some of them are not used directly by facelets code. Really it is just one or two missing lines but we need to get this done before release.
I did a full review of every facelet class and it was found that:
org.apache.myfaces.view.facelets.tag.jsf.core.AttributeHandler
does not implements the interface:
javax.faces.view.facelets.AttributeHandler
And it should be.