[ticket/12563] Changes 2 language variables to better understandable names

PHPBB3-12563
[ticket/12563] Removes strintf in acp_styles.php and shorts up <a>

PHPBB3-12563
Merge pull request #2571 from Crizz0/ticket/12563

[ticket/12563] Changes 2 style specific language variables for better understanding

* Crizz0/ticket/12563:
  [ticket/12563] Removes strintf in acp_styles.php and shorts up <a>
  [ticket/12563] Changes 2 language variables to better understandable names