I've added so that a ruby instance of each event type is created when an event is allocated and initialized. Left to do is to keep reference to these objects inside the event instance and to force the event type instances to keep a reference back to their original event. This is to make sure that the garbage collector keep them together in memory at all times. Also something I must do is to check the event's type in the initialize method so that we will always only create ONE of these "child" instances.
This way we won't need to allocate any unnecessary memory except if the developer specifically request a new event type instance. For example: SFML::Event::Key.new
git-svn-id: https://sfml.svn.sourceforge.net/svnroot/sfml/branches/sfml2@1606 4e206d99-4929-0410-ac5d-dfc041789085
