Remove Hash use from Uglify options because it breaks it.

Author: jdalton

lib/common/uglify.options.js

@@ -1,11 +1,6 @@
 'use strict';
 
-var util = require('./util'),
-    Hash = util.Hash;
-
-/*----------------------------------------------------------------------------*/
-
-module.exports = new Hash({
+module.exports = {
   'compress': {
     'pure_getters': true,
     'unsafe': true,
@@ -20,4 +15,4 @@ module.exports = new Hash({
     'comments': /^!|@cc_on|@license|@preserve/i,
     'max_line_len': 500
   }
-});
+};