Outdated call to preg_replace with e modifier breaks custom BBCode creation in HHVM and PHP 7+

In acp_bbcodes.php, there is a call to preg_replace using the e modifier that breaks the token- incrementing loop, naturally resulting in all tokens beyond the first being left at $1 and replaced with original first token's value during use.

Because of the type of issue, please note this only happens on codes that use 2+ tokens. Built in and single tokens continue to work as intended.

I have offered a fix for this issue in this thread which works flawlessly on my test box.

Note also I have listed my HHVM in the environment section, but as of vanilla PHP version 5.5, the e modifier was depreciated, and as of PHP 7 it is completely removed.

Also I marked priority as minor as it doesn't happen with the most used versions of PHP, but I would consider custom bbcodes not working to be a major issue given their level of use.