[ticket/12329] Add <div> container to index blocks (stats, etc.)

PHPBB3-12329
[ticket/12329] changed all CSS classes to ".stat-block"

PHPBB3-12329
Merge remote-tracking branch 'paybas/ticket/12329' into develop-ascraeus

* paybas/ticket/12329:
  [ticket/12329] changed all CSS classes to ".stat-block"
  [ticket/12329] Add <div> container to index blocks (stats, etc.)