[ticket/12604] Fix wrong padding when no notifications

Added a class to the <li> when the <li> represents that there's no
notifications (no_notifications) and
Added a CSS rule that matches the change to the HTML source for when
there's no notifications.

PHPBB3-12604
[ticket/12611] Remove phpBB Group copyright notice from .gifs

PHPBB3-12611
Merge pull request #2511 from Marshalrusty/ticket/12611

[ticket/12611] Remove phpBB Group copyright notice from .gifs

* Marshalrusty/ticket/12611:
  [ticket/12611] Remove phpBB Group copyright notice from .gifs
Merge pull request #2506 from brunoais/ticket/12604

[ticket/12604] Fix wrong padding when no notifications

* brunoais/ticket/12604:
  [ticket/12604] Fix wrong padding when no notifications
[ticket/12614] Make the post buttons always visible.

PHPBB3-12614
Merge pull request #2513 from prototech/ticket/12614

[ticket/12614] Make the post buttons always visible.

* prototech/ticket/12614:
  [ticket/12614] Make the post buttons always visible.
[ticket/12594] Fix file headers of new files

PHPBB3-12594
[ticket/12594] Update file header in non-php files

PHPBB3-12594
Merge pull request #2520 from nickvergessen/ticket/12594

[ticket/12594] Fix file headers of new files

* nickvergessen/ticket/12594:
  [ticket/12594] Update file header in non-php files
  [ticket/12594] Fix file headers of new files
[ticket/12621] schema.json is not up to date with migration files

PHPBB3-12621
Merge pull request #2522 from PayBas/ticket/12621

[ticket/12621] schema.json is not up to date with migration files

* PayBas/ticket/12621:
  [ticket/12621] schema.json is not up to date with migration files