dirname() is a slow function compared with __DIR__ and using
'/../'. Moodle has a large number of legacy files that are included
each time a page loads and is not able to use an autoloader as it is
functional code. This allows those required includes to perform as
best as possible in this situation.
Moving stuff from lib.php into static methods in localib.php. Removing
things from workshop core that were implemented in a subplugin. Dropping
stuff related to features not to be implemented in 2.0.