Implement IDOMElement::setAttribute

    Implement IDOMElement::setAttribute

        This method was mistakenly called "setResult" in DOMCore.idl, so I
        fixed that as well.

        Needed for <rdar://problem/5314906>.

        Reviewed by Ada.

        * DOMCoreClasses.cpp:
        (DOMElement::setAttribute): Implemented/renamed.
        * DOMCoreClasses.h: Renamed setResult => setAttribute.
        * DOMHTMLClasses.h: Ditto.
        * Interfaces/DOMCore.idl: Ditto.

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@24536 268f45cc-cd09-0410-ab3c-d52691b4dbfc