Right now, the Singleton pattern in Subtitles relies on PHP 5 >= 5.3.0. Specifically, get_called_class and new static (late static binding) are not compatible with PHP 5.2.4, which WordPress still supports. I need to 1) see if there's a better way to handle this design pattern that accounts for PHP 5.2.4 and 2) see if I even need it at all.