Check whether the Composer ClassLoader has already been loaded #64
Description
Check whether the Composer ClassLoader has already been loaded.
We load the Composer ClassLoader in src/Templates/autoload.php.tmpl. It is possible that other modules are also shipped with Composer. If ClassLoader already loaded this will cause in an error. Maybe we could check before we do require_once DIR_FS_DOCUMENT_ROOT . '/vendor/composer/ClassLoader.php';