query by point suggestion

[Grzegorz Myrda]

In subjective opinion :) it would be better if querying by clicking on the
image, would search and return results from layers that are visible (on and
at proper scale), rather than all layers from mapfile.
Getting results from layers we are not watching (default on, but its
maxscale under current scale) is maybe sometimes useful but more often
confusing.

Grzegorz