https://bugs.webkit.org/show_bug.cgi?id=18421
        <rdar://problem/5857369> XMLHttpRequest does not properly encode & and < in outgoing messages

        Test: http/tests/xmlhttprequest/serialize-document.html

        * bindings/js/JSXMLHttpRequestCustom.cpp:
        (WebCore::JSXMLHttpRequest::send): Use createMarkup() instead of Document::toString().

        * dom/Attr.cpp:
        * dom/Attr.h:
        * dom/Document.cpp:
        * dom/Document.h:
        * dom/DocumentFragment.cpp:
        * dom/DocumentFragment.h:
        * dom/Element.cpp:
        * dom/Element.h:
        * dom/Entity.cpp:
        * dom/Entity.h:
        * dom/EntityReference.cpp:
        * dom/EntityReference.h:
        * dom/Node.h:
        * dom/Text.cpp:
        * dom/Text.h:
        * html/HTMLElement.cpp:
        * html/HTMLElement.h:
        Removed most Node::toString() methods, which were massively wrong, and only used for
        XMLHttpRequest::send(). The remanining ones are still used in markup.cpp, but should probably
        be folded into it for consistency.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@33577 268f45cc-cd09-0410-ab3c-d52691b4dbfc