Reviewed by Eric Seidel and Adam Roben.

        More fix for https://bugs.webkit.org/show_bug.cgi?id=21260
        Unbounded memory growth when churning elements with anonymous event handler functions
        
        Simplified some EventHandler creation code.
        
        Removed a pile of code whose sole purpose was to allow SVG event handlers
        to supply a parameter named "evt" instead of the normal "event", and
        replaced it with a single parameter to JSLazyEventListener's constructor
        specifying the parameter name to use.

        * bindings/js/JSDOMWindowBase.h:
        * bindings/js/JSLazyEventListener.cpp:
        (WebCore::JSLazyEventListener::JSLazyEventListener):
        (WebCore::JSLazyEventListener::parseCode):
        * bindings/js/JSLazyEventListener.h:
        (WebCore::JSLazyEventListener::create):
        * bindings/js/ScriptController.cpp:
        (WebCore::ScriptController::createInlineEventListener):
        * bindings/js/ScriptController.h:
        * dom/Document.cpp:
        (WebCore::Document::createEventListener):



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@42579 268f45cc-cd09-0410-ab3c-d52691b4dbfc