xhr doesn't support qs.

Author: pluma

lib/connection.js

@@ -3,6 +3,7 @@
 
 var noop = require('./util/noop'),
   extend = require('extend'),
+  querystring = require('querystring'),
   request = require('request'),
   ArangoError = require('./error'),
   jsonMime = /\/(json|javascript)(\W|$)/;
@@ -43,13 +44,13 @@ extend(Connection.prototype, {
       url = url.replace(/\/[^\/]+\/..\//, '/');
       if (oldUrl === url) break;
     }
+    if (opts.qs) url += '?' + (typeof opts.qs === 'string' ? opts.qs : querystring.stringify(opts.qs));
 
     request({
       url: url,
       auth: opts.auth || this.config.auth,
       headers: extend(headers, this.config.headers, opts.headers),
       method: (opts.method || 'get').toUpperCase(),
-      qs: opts.qs,
       body: body,
       encoding: 'utf-8'
     }, function (err, response, rawBody) {