We are dealing with strings for comparison

Because OpenLayers.Util.getParameters turns comma delimited values into
arrays, comparing e.g. bbox values in urls will return false. By
introducing a splitArgs option, we can use getParameters in a way that
leaves such values as strings and makes them comparable in
OpenLayers.Util.isEquivalentUrl.
Merge pull request #974 from ahocevar/typecast

Zooming with TileManager does not work with GeoExt 1.x and webkit browsers. r=@bartvde