Tiles Loading when Layer Invisible

This is a duplicate of #937, but the description should be merged with that one so that this is clear.

update from gregm:

I have corrected it in Map.js setCenter function, with some additional lines
of checks and conditions inside 'for' loop.
It works for me, but I do not know if it is good for any case.
Code below:
>
> for (var i = 0; i < this.layers.length; i++) {
>                 var layer = this.layers[i];
>                 if (!layer.isBaseLayer) {
>
>                     var moveLayer;
>                     var inRange = layer.calculateInRange();
>                     if (layer.inRange != inRange) {
>                         // Layer property has changed. We are going
>                         // to call moveLayer so that the layer can be
> turned
>                         // off or on.
>                         layer.inRange = inRange;
>                         //do NOT download tiles if not in scale limit
>                         moveLayer = (layer.visibility && layer.inRange);
> //
> was ... = true;
>                         //switch off layer after going beyond scale limit
>                         if (layer.visibility && !layer.inRange)
>                             layer.setVisibility(false);
>                         this.events.triggerEvent("changelayer");
>                     } else {
>                         // If nothing has changed, then we only move the
> layer
>                         // if it is visible and inrange.
>                         moveLayer = (layer.visibility && layer.inRange);
>                         //switch off layer after going beyond scale limit
>                         if (layer.visibility && !layer.inRange)
>                             layer.setVisibility(false);
>                     }
>                     if (moveLayer) {
>                         layer.moveTo(bounds, zoomChanged, dragging);
>                     }
>                 }
>             }



Greg

Merged ticket description into #937.