added ignoring gadgets if click already caused animation event action

added ignoring gadgets if click already caused animation event action

Before, even though executing more than one event action triggered by
clickable global animations was already prevented, further processing
of mouse clicks by gadgets at the same position was still performed if
the global animation style was set to "passthrough_clicks", which could
lead to more than one gadgets being triggered at the same time by a
single click on a clickable global animation, with potentially unwanted
side effects.

Now, mouse clicks that already triggered an event action (which could
be a gadget) are not processed by the standard gadget handling anymore.