[ticket/11574] Try to load updated service.yml before the default one

PHPBB3-11574
[ticket/11574] Find language files in update/new before throwing an error

PHPBB3-11574
[ticket/11574] Require new files in database_update.php and add a class loader

PHPBB3-11574
[ticket/11574] Require new files in install/index.php and add a class loader

PHPBB3-11574
[ticket/11574] Load new language files whenever possible

PHPBB3-11574
[ticket/11574] Use request object rather then request_var function

PHPBB3-11574
[ticket/11574] Add correct language parameter to return links

PHPBB3-11574
[ticket/11574] Create phpbb_log object before using it.

PHPBB3-11574
[ticket/11574] Include vendor into update packages

PHPBB3-11574
[ticket/11574] Use log object instead of old function

PHPBB3-11574
[ticket/11574] Only fall back to install/update versions, when IN_INSTALL ;)

PHPBB3-11574
[ticket/11574] Include normalizer so it loads form the correct directory

PHPBB3-11574
[ticket/11574] Use alternate DI config file for updater

PHPBB3-11574
[ticket/11574] Make install language filename less crazy

PHPBB3-11574
[ticket/11574] Fix various path issues in the updater

PHPBB3-11574