Move more methods from Frame into ScriptController
        https://bugs.webkit.org/show_bug.cgi?id=20294

        Finally finish more of the work which Darin started long ago
        Move a few more Frame methods into ScriptController.
        I also took this opportunity to clean up some of the plugin
        code as well, and moved some of that into ScriptController.

        I removed Frame::clearScriptController() and ScriptController::clear() is now clearWindowShell()

        No functional changes, thus no test cases.

        * GNUmakefile.am:
        * WebCore.NPAPI.exp:
        * WebCore.base.exp:
        * WebCore.pro:
        * WebCore.vcproj/WebCore.vcproj:
        * WebCore.xcodeproj/project.pbxproj:
        * bindings/js/ScriptController.cpp:
        (WebCore::ScriptController::ScriptController):
        (WebCore::ScriptController::~ScriptController):
        (WebCore::ScriptController::bindingRootObject):
        (WebCore::ScriptController::creat...