Add filter to allow for changing of the report class files.
This will allow 3rd party plugins to use this function to extend the
reporting. Currently this can only include files in the woocommerce plugin
directory itself.
The superglobals $_GET and $_REQUEST are already decoded. Using
urldecode() on an element in $_GET or $_REQUEST could have unexpected
and dangerous results.
See Notes:
http://us1.php.net/manual/en/function.urldecode.php