[ticket/12517] Correctly call $log->add in prune shadow topics

PHPBB3-12517
[ticket/12526] Fix undefined index: filesize when editing PM with attachments.

PHPBB3-12526
Merge pull request #2439 from prototech/ticket/12526

[ticket/12526] Fix undefined index: filesize when editing PM with attachments.

* prototech/ticket/12526:
  [ticket/12526] Fix undefined index: filesize when editing PM with attachments.
Merge pull request #2438 from marc1706/ticket/12517

[ticket/12517] Correctly call $log->add in prune shadow topics

* marc1706/ticket/12517:
  [ticket/12517] Correctly call $log->add in prune shadow topics
[ticket/12451] Fix whitespace in posting.php lang file

PHPBB3-12451
Merge pull request #2442 from Elsensee/ticket/12451-2

[ticket/12451] Fix whitespace in posting.php lang file

* Elsensee/ticket/12451-2:
  [ticket/12451] Fix whitespace in posting.php lang file
[ticket/12518] Add event to overwrite the allow edit and delete conditions

PHPBB3-12518
[ticket/12518] Add event to overwrite the cannot edit condition in posting.php

PHPBB3-12518
Merge remote-tracking branch 'nickvergessen/ticket/12518' into develop-ascraeus

* nickvergessen/ticket/12518:
  [ticket/12518] Add event to overwrite the cannot edit condition in posting.php
  [ticket/12518] Add event to overwrite the allow edit and delete conditions
[ticket/12518] Apply De Morgan to make the conditions easier to read

PHPBB3-12518
Merge pull request #2446 from nickvergessen/ticket/12518

[ticket/12518] Apply De Morgan to make the conditions easier reasable

* nickvergessen/ticket/12518:
  [ticket/12518] Apply De Morgan to make the conditions easier to read
[ticket/12534] Do not abuse errorbox for en/disable confirmation of extensions

PHPBB3-12534
[ticket/12534] Do not use errorbox for multi steps

PHPBB3-12534
[ticket/12534] Fix filter for functional tests

PHPBB3-12534
Merge remote-tracking branch 'nickvergessen/ticket/12534' into develop-ascraeus

* nickvergessen/ticket/12534:
  [ticket/12534] Fix filter for functional tests
  [ticket/12534] Do not use errorbox for multi steps
  [ticket/12534] Do not abuse errorbox for en/disable confirmation of extensions