Merge pull request #4895 from rubencm/ticket/15289
[ticket/15289] Allow to configure storage from acp
* github.com:phpbb/phpbb: (38 commits)
[ticket/15289] Add phpdoc
[ticket/15289] Remove common language from acp module
[ticket/15289] Check form
[ticket/15289] Use empty instead of count
[ticket/15289] Language fixes
[ticket/15289] Add missing files
[ticket/15289] Use twig syntax in variables
[ticket/15289] Use lang_defined()
[ticket/15289] Dont use short names
[ticket/15289] Dont use short names
[ticket/15289] Use Twig includes
[ticket/15289] Update acp module
[ticket/15289] Fix comment typo
[ticket/15289] Fix show field description
[ticket/15289] Update event
[ticket/15289] Remove switch since there is only one mode
[ticket/15289] Improve error messages
[ticket/15289] Fix code style
[ticket/15289] Update acp storage
[ticket/15289] Update acp storage template
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