[ticket/11373] Prune old read notifications with cron

PHPBB3-11373
[ticket/11373] Use inheritdoc

PHPBB3-11373
Merge branch 'develop' of github.com:phpbb/phpbb3 into ticket/11373

# By Joseph Warner (188) and others
# Via Andreas Fischer (41) and others
* 'develop' of github.com:phpbb/phpbb3: (435 commits)
  [ticket/11745] Correct language, coding guidelines
  [ticket/11828] Fix greedy operators in lexer
  [ticket/11835] Fix ucp_auth_link adding in migration
  [prep-release-3.0.12] Remove changelog entry for ticket that was not resolved.
  [ticket/develop/11832] Fix path detection
  [ticket/11833] Prevent Twig errors from invalid template loops using BEGINELSE
  [ticket/11833] Fix bad template loop
  [feature/oauth] Fix tabindex
  [ticket/11816] !$DOESNT_EXIST test
  [ticket/9550] Add the core.viewtopic_post_rowset_data event to viewtopic.php
  [ticket/11829] Use report_closed to determine status in MCP report_details
  [ticket/11825] Move schema_data.php into includes/ instead of phpbb/
  [ticket/11215] Remove unnecessary comment
  [ticket/11755] MySQL upgrader out of date
  [prep-release-3.0.12] Update Changelog for 3.0.12-RC3 release.
  [prep-release-3.0.12] Bumping version number for 3.0.12-RC3.
  [ticket/11823] Set up nginx server to match PHP files with characters after .php
  [ticket/11812] Fix empty define
  [ticket/11818] Update Symfony dependencies to 2.3.*
  [feature/oauth] Fix bug on ucp_auth_link related to error display
  ...
Merge pull request #1622 from EXreaction/ticket/11373

[ticket/11373] Prune old read notifications with cron