Merge: nitunit: fix before and after methods

Before and after method were not actually called in the test suite process.

This PR enables the compilation and run of these methods.

The new behavior is: if the `before_module` test case fails, all the test cases and the `after_module` are skipped and marked as failed.

Pull-Request: #2359
Reviewed-by: Jean-Christophe Beaupré <jcbrinfo.public@gmail.com>
Reviewed-by: Jean Privat <jean@pryen.org>