Delegate javascript debugging to Script and V8 debugger clients.

The appropriate client handles the debugging based on the service available at the server side.

Change-Id: I46b66036f700fc7e45e8b38cef7f1ce1445b1122
Reviewed-on: http://codereview.qt.nokia.com/2497
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Kai Koehne <kai.koehne@nokia.com>

src/libs/qmljsdebugclient/qdeclarativedebugclient_p.h

@@ -88,7 +88,7 @@ public:
 
     Status status() const;
 
-    void sendMessage(const QByteArray &);
+    virtual void sendMessage(const QByteArray &);
 
 protected:
     virtual void statusChanged(Status);