OpenLayers: update to 2.13dev

Based on dd4ae804 (Tobias' private OL clone, 2.13 branch), which has
the google layer patches of ahocevar applied on 2303cadf (OL 2.13).
map.js: add TileManager to make the map more responsive on mobile devices
map.js: set transition effect to 'map-resize' on map overlays
map.js: enable fallThrough which is needed by the GraphicLayerSwitcher
OpenLayers.css: include changes from 2.13dev
assets/bundles: use closure for openlayers bundle