Merged in bugfix/MAPG-148-fix-xmlhttp-responsetype-error (pull request #118)

MAPG-148 set xhr responseType after xhr open() because it is accepted by all browsers

public/static/js/mapguesser.js

@@ -2,11 +2,12 @@ var MapGuesser = {
     httpRequest: function (method, url, callback, data) {
         var xhr = new XMLHttpRequest();
 
-        xhr.responseType = 'json';
         xhr.onload = callback;
 
         xhr.open(method, url, true);
 
+        xhr.responseType = 'json';
+
         if (method === 'POST') {
             if (typeof data === 'undefined') {
                 data = new FormData();