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))
Merge pull request #59 from aogriffiths/patch-1

Update wrench.js