(HTMLInputElementImp::handleMutation): Process the disabled, tabindex, and type attributes
(HTMLInputElementImp::HTMLInputElementImp, HTMLInputElementImp::eval): Refine
(HTMLFormControlImp::HTMLFormControlImp): Refine
(HTMLButtonElementImp::handleMutation): Fix bugs
(HTMLAnchorElementImp::HTMLAnchorElementImp, HTMLAnchorElementImp::handleMutation): Refine
(HTMLLinkElementImp::HTMLLinkElementImp, HTMLLinkElementImp::handleMutation): Refine