[ticket/11422] Increment assets when database_update is complete

PHPBB3-11422
Merge pull request #1315 from bantu/ticket/11469

[ticket/11469] Add SQL insert buffer allowing easier handling of multi i...
Merge pull request #1285 from EXreaction/ticket/11422

[ticket/11422] Increment assets when database_update is complete
[ticket/11403] phpbb_notification_manager: Use SQL multi insert in batches.

PHPBB3-11403
[ticket/11403] Use an instance of phpbb_db_sql_insert_buffer instead.

PHPBB3-11403