Trivial Description
AjaxButton and AjaxSubmitLink supply the submitted form in their submit hooks, e.g.:
protected void onSubmit(AjaxRequestTarget target, Form<?> form)
The form is superfluous, since it is already available via #getForm().
We decided to remove this parameter, bringing the hooks in line with the new static lambda factories, e.g.:
public static AjaxSubmitLink onSubmit(String id, WicketBiConsumer<AjaxSubmitLink, AjaxRequestTarget> onSubmit)
Relevant discussion: http://wicket-dev.markmail.org/thread/vzzntc6wbjub3fad