[ticket/12718] Use remove_topic_from_statistic() for delete_topic

PHPBB3-12718
[ticket/12718] Update docblock

PHPBB3-12718
[ticket/12718] Add tests to check user_posts on post deletion

PHPBB3-12718
[ticket/12718] Fix docblocks

PHPBB3-12718
[ticket/12718] Fix spacing and type casting

PHPBB3-12718
[ticket/12718] Use a separate variable for sql query

PHPBB3-12718
[ticket/12948] Remove no longer needed opcache workaround. Travis has 5.5.15.

PHPBB3-12948
[ticket/12693] Don't try to check the composer.phar file

PHPBB3-12693
Merge remote-tracking branch 'github-nicofuma/ticket/12693' into develop-ascraeus

* github-nicofuma/ticket/12693:
  [ticket/12693] Don't try to check the composer.phar file
Merge pull request #2624 from dhruvgoel92/ticket/12718

[ticket/12718] Use remove_topic_from_statistic() for delete_topic

* dhruvgoel92/ticket/12718:
  [ticket/12718] Use a separate variable for sql query
  [ticket/12718] Fix spacing and type casting
  [ticket/12718] Fix docblocks
  [ticket/12718] Add tests to check user_posts on post deletion
  [ticket/12718] Update docblock
  [ticket/12718] Use remove_topic_from_statistic() for delete_topic
Merge pull request #2848 from bantu/ticket/12948

[ticket/12948] Remove no longer needed opcache workaround. Travis has 5.5.15