Bump to v4.7.0.

_Stack.js

@@ -22,7 +22,7 @@ function Stack(values) {
   }
 }
 
-// Add functions to the `Stack` cache.
+// Add methods to `Stack`.
 Stack.prototype.clear = stackClear;
 Stack.prototype['delete'] = stackDelete;
 Stack.prototype.get = stackGet;