Sets/gets the name identifier which will be used
          to pass the context between the objects in the composite.
        
          The context name should be set before any objects are added to the
          composite. The name takes effect when the object is added so changing
          the property will not change the context name of the already added
          objects. To avoid mistakes avoid changing the context's name during
          the composite management.
          How the context name is used:
          If the object is a script the context (VaryDispCtx
          object) is visible to the script as global namespace with the
          specified name.
          If the object is an ordinary COM object a method with this name
          will be called with one parameter - the VaryDispCtx object. So if the
          COM object is especially written for usage in composites it will be
          able to record and use it further.