Use layer id instead of name for hash

- to make it work across languages and on translation changes
- with legacy support for old names

js/LayersConfig.js

@@ -12,6 +12,15 @@ BR.LayersConfig = L.Class.extend({
         'Waymarked_Trails-Hiking'
     ],
 
+    legacyNameToIdMap: {
+        'OpenStreetMap': 'standard',
+        'OpenStreetMap.de': 'osm-mapnik-german_style',
+        'OpenTopoMap': 'OpenTopoMap',
+        'Esri World Imagery': 'Esri.WorldImagery',
+        'Cycling (Waymarked Trails)': 'Waymarked_Trails-Cycling',
+        'Hiking (Waymarked Trails)': 'Waymarked_Trails-Hiking'
+    },
+
     initialize: function (map) {
         this._map = map;