[ticket/12025] Post Preview no longer shows warnings

https://tracker.phpbb.com/browse/PHPBB3-12025

PHPBB3-12025
[ticket/12025] Don't show any error on preview if the message is empty

PHPBB3-12025
[ticket/12025] Fixing the condition....

PHPBB3-12025
[ticket/12451] Split TOO_FEW_CHARS_LIMIT for plurals

PHPBB3-12451
[ticket/12451] Split TOO_MANY_CHARS vars for plurals

PHPBB3-12451
[ticket/12451] Use new line to concatenate strings

PHPBB3-12451
[ticket/12451] Remove duplicated lang var

PHPBB3-12451
[ticket/12500] Set a title attribute in user.img()

PHPBB3-12500
[ticket/12325] Generate the list of the deleted files and folders

https://tracker.phpbb.com/browse/PHPBB3-12325

PHPBB3-12325
[ticket/12325] Add files located in deleted dirs

PHPBB3-12325
[ticket/12325] Add visibilities

PHPBB3-12325
[ticket/12325] Change private function to protected

PHPBB3-12325
[ticket/12025] Apply DeMorgan

PHPBB3-12025
[ticket/12440] Set browser URL to point to specific post when using view=unread

PHPBB3-12440
[ticket/12325] Doc blocks

PHPBB3-12325
[ticket/12325] Use \RecursiveDirectoryIterator

PHPBB3-12325
[ticket/12440] Use a more generic approach for replacing the URL.

PHPBB3-12440
[ticket/12402] CAPTCHA plugin migration fails to detect missing plugins

PHPBB3-12402
[ticket/12510] Convert & to &amp; in build_url() when no params are stripped.

PHPBB3-12510
[ticket/12428] Incorrect from version in database update log entry

https://tracker.phpbb.com/browse/PHPBB3-12428

PHPBB3-12428