Reviewed by Adam and Steve.
        
        Implemented some DOM methods and other fixes for <rdar://problem/5311601>.
        
        * DOMCoreClasses.cpp:
        (DOMNode::ownerDocument): implemented
        (DOMDocument::getComputedStyle): get the DOMElement via QueryInterface
        (DOMElement::QueryInterface):
        * DOMHTMLClasses.cpp:
        (DOMHTMLDocument::body): fixed leak
        (DOMHTMLFormElement::action): implemented
        (DOMHTMLFormElement::method): ditto
        (DOMHTMLInputElement::form): ditto
        (DOMHTMLTextAreaElement::form): ditto
        * Interfaces/DOMHTML.idl: IDOMHTMLInputElement should inherit from IDOMHTMLElement



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@24630 268f45cc-cd09-0410-ab3c-d52691b4dbfc