Update wrench.js

Fixes a bug (not sure if has been reported).

`copyDirRecursive` calls itself from the `rmdirRecursive` callback when newDir exists. It should call itself with the original copyDirRecursive arguments, not the callback arguments. 

Also `fun.apply(thisArg, argsArray)` expects argsArray to be an array (see [here](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Function/apply)) but `arguments` is not an array (see [here](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions_and_function_scope/arguments))

Very similar to [pull request 56](https://github.com/ryanmcgrath/wrench-js/pull/56) (I wrote my code before I noticed danielholmes did a similar fix).