layerswitcher in IE leaks memory like a seive

[euzuro]

double circular reference

[euzuro]

dont add circular refs to inputElem. bind them into a context.

[euzuro]

note for posterity:

instead of doing:

        this.baseLayersDiv.innerHTML = "";
        this.baseLayerInputs = new Array();
        
        this.dataLayersDiv.innerHTML = "";
        this.dataLayerInputs = new Array();

we should really cycle through and properly destroy each thing. but for now, this works.

[euzuro]

as per previous comment, i have refitted this patch so that it does things the proper way, which means cleaning up after itself -- not just letting things slide until the unloadCache() is called. Also, this improvement to the patch fixes a problem in the updateMap() function where we were still relying on the layer to be tagged off of the inputElement (the circular ref we are here deleting)

[euzuro]

one little tiny but was leftover from original. this.checked -> this.inputElem.checked

[crschmidt]

r2918.