Change any option to tear the menu down and build it again with the new
settings. The configuration is kept in the URL, so a reload comes back
to the same one — which is what makes
remember testable here.
remember on: the
state comes back. The storage readout says which of the two stores did
it — over file:// a cookie will not work in Chrome,
but localStorage does.
pushBody on and the menu open, narrow the window
below 480 pixels: the plugin stops pushing, and the body margin has to
go back with it.
destroy() left a handler behind.