Added PHP 5.4 compatibility

Feel free to use this pull request however you like, either merge the changes or at least use it as a comparison of how the add-on has been made PHP 5.3 and below compatible.

As explained on XenForo.com it's just a simple case of adjusting the array syntax.

Great work on this. Making it 5.3 compatible means that even more sites can now benefit from your great work.

Chris.