Add some badges to show status of the project.
Add ne method getRunonces() to retrieve the list of registered run once files.
New method RunonceManager::clearRunonces();
Add test cases to check if a runonce being added is already reachable from within Contao.

This is needed to prevent duplicate execution if a runonce.php throws an exception and
is called later on from the core again.
Add checks if a runonce being added is already reachable from within Contao.

This is needed to prevent duplicate execution if a runonce.php throws an exception and
is called later on from the core again.
We now ignore runonce.php files that are already present within the mapped directories.