Special event dispatcher that is only used for CRAddFeature morph.
It is necessary to make sure that all the red button downs are handled by
the CRAddFeatureMorph and not by its submorphs.
Exception: The button-submorphs have to handle the events itself.

	dispatching	top
	dispatchMouseDown:with: This method is very similar to the super class method. The only difference is that it lets only buttons and CRAddFeatureMorphs handle events