New Class smooths out installation of parent plugs

This new MP_CORE_Licensed_Parent_Plugin_Installation_Routine class makes it so that when you install a plugin that is licensed and is a parent to other plugins (that is, the parent plugn's license can be used for its dependant plugins), it auto installs them so the user doesn't have to click "Instal All Items". That still works if the user clicks cancel however
Changelog update