Loader: support json files where multiline strings are split as string-arrays

package.json

@@ -12,6 +12,7 @@
     "font-awesome": "^4.7.0",
     "i18next-client": "^1.11.4",
     "ip-location": "^1.0.1",
+    "json-multiline-strings": "^0.1.0",
     "leaflet": "^1.0.3",
     "leaflet-geosearch": "^2.4.0",
     "leaflet.locatecontrol": "^0.61.0",

src/OpenStreetBrowserLoader.js

@@ -1,4 +1,5 @@
 var OverpassLayer = require('overpass-layer')
+var jsonMultilineStrings = require('json-multiline-strings')
 
 function OpenStreetBrowserLoader () {
   this.types = {}
@@ -31,6 +32,7 @@ OpenStreetBrowserLoader.prototype.getCategory = function (id, callback) {
     }
 
     var data = JSON.parse(req.responseText)
+    data = jsonMultilineStrings.join(data, { exclude: [ [ 'const' ] ] })
 
     this.getCategoryFromData(id, data, function (err, category) {
       if (category) {