Removed old test for through source changes
Through models and AssociativeList now uses id for uniqueness check when available
Association are now setup on first attr call so that all Classes are available
Waiting queue now works on all indexed attrs, not just id
Now overriding all set<indexed attr> methods instead of just setId to search for a cached model
Moved waiting logic to set<indexed attr> methods
Through models now store the ref counts on the original object so it doesn't rely on unique instances.