ExtractFunctions() has become GetModuleInterface() and now returns the name of the module's class. I discovered that PHP allows you to instantiate that class like so
$class_name = GetModuleInterface();
$instance = new $class_name;
I like this solution a lot better because now I dont need that ugly Function field in my database like I had before, I dont have call_user_function() or an ugly array of functions in my code like I did when I returned an array of functions, and generally it seems like the code is simpler.
Before I decided to try this I tried to take jumpjumpjump up on his suggestion to look at MediaWiki's namespaces but I guess I suck at PHP or I dont get MediaWiki's code because I didnt understand what was going on. I looked in a few files but I didnt find one that included Namespace.php nor did I understand the significance of Namespace.php. [oh]