These patches are based on code changes contributed by Alex Pagnoni
<alex@ampoliros.com>
They allow to obtain different behaviours for the layers menus.

We suggest to use example-hormenu.php as the demo of these patches
and to *click* on the menu bar items to understand what is going on.

The two patches differ w.r.t. the shutdown of visible layers.
onclick.patch:
        click to shutdown the visible layers.
onclick-simple.patch:
        the shutdown of visible layers relies on the timeout feature.

To obtain yet another different behaviour, you can use the onclick.patch
and then set
useTimeouts = 1;
in layersmenu.js

Alex Pagnoni
Marco Pratesi