[feature/avatars] Add service containers for avatars

PHPBB3-10018

phpBB/includes/avatar/driver/interface.php

@@ -21,6 +21,13 @@ if (!defined('IN_PHPBB'))
 */
 interface phpbb_avatar_driver_interface
 {
+	/**
+	* Returns the name of the driver.
+	*
+	* @return string		Name of wrapped driver.
+	*/
+	public function get_name();
+
 	/**
 	* Get the avatar url and dimensions
 	*