removed global dependency from grammer

lib/grammar.js

@@ -9,6 +9,7 @@
       return [patternString, '$$ = $1;', options];
     }
     action = (match = (action + '').match(unwrap)) ? match[1] : ("(" + (action) + "())");
+    action = action.replace(/\b(?:[A-Z][a-z]+Node|Expressions)\b/g, 'yy.$&');
     return [patternString, ("$$ = " + (action) + ";"), options];
   };
   grammar = {