Simplify uglify options.

lib/common/uglify.options.js

@@ -12,12 +12,9 @@ module.exports = {
     'unsafe': true,
     'warnings': false
   },
-  'mangle': {
-    'except': ['define']
-  },
   'output': {
     'ascii_only': true,
-    'comments': /^!|@cc_on|@license|@preserve/i,
+    'comments': /@license/,
     'max_line_len': 500
   }
 };