Supports include and keys in AV.Object#fetch

Author: killme2008

lib/object.js

@@ -769,12 +769,30 @@
      * Fetch the model from the server. If the server's representation of the
      * model differs from its current attributes, they will be overriden,
      * triggering a <code>"change"</code> event.
+     * @param {Object} options Optional Backbone-like options object to be
+     *     passed in to set. Also you can set 'keys' and 'include' options.
      * @return {AV.Promise} A promise that is fulfilled when the fetch
      *     completes.
      */
     fetch: function(options) {
+      var include = null;
+      var keys = null;
+      if(options) {
+        var processOpt = function(k) {
+          if(options[k]){
+            if(_.isArray(options[k])) {
+              return options[k].join(',');
+            } else {
+              return options[k];
+            }
+          }
+        };
+        include = processOpt('include');
+        keys = processOpt('keys');
+      }
       var self = this;
-      var request = AV._request("classes", this.className, this.id, 'GET');
+      var request = AV._request("classes", this.className, this.id, 'GET',
+                                { include: include, keys: keys});
       return request.then(function(response, status, xhr) {
         self._finishFetch(self.parse(response, status, xhr), true);
         return self;