Scroll update

This PR contains three commit (last one slipped in :).

- ToolBar behaved oddly. contentRect.y() * mResolution should be used there
- mRootFrameScrolling removed
- Remove newWindowRequested as it should not be used. If that is used for creating sub windows then you are returning wrong unique id from CreateNewWindowRequested. Thus, should not be used. Instead QMozViewCreator should be implemented by MozView users.