[ticket/12953] Page title not updated when notifications are marked as read

PHPBB3-12953
[ticket/12958] Remove subsilver2 for phpBB 3.2

PHPBB3-12958
[ticket/12958] Remove more references of subsilver2

PHPBB3-12958
Merge remote-tracking branch 'nickvergessen/ticket/12958' into develop

* nickvergessen/ticket/12958:
  [ticket/12958] Remove more references of subsilver2
  [ticket/12958] Remove subsilver2 for phpBB 3.2
Merge pull request #2855 from Geolim4/ticket/12953

[ticket/12953] Page title not updated when notifications are marked as read

* Geolim4/ticket/12953:
  [ticket/12953] Page title not updated when notifications are marked as read
Merge branch 'develop-ascraeus' into develop

* develop-ascraeus:
  [ticket/12953] Page title not updated when notifications are marked as read