Add alias for skip/offet (mongoose)

lib/adapters/mongoose.js

@@ -145,6 +145,8 @@ MongooseAdapter.prototype.all = function all(model, filter, callback) {
     }
     if (filter.skip) {
         query.skip(filter.skip);
+    } else if (filter.offset) {
+        query.skip(filter.offset);
     }
     query.exec(function (err, data) {
         if (err) return callback(err);