Error correction in bi-directional feature model

The features "2 Wheel Drive" and "4 Wheel Drive" should be alternatives
Made changes to folders and created new model

Folder structure was tidied up to support additional models with
attached notes.
Created a new feature model that uses three trees instead of two and
created some notes for that model.
Removed the Notes panel from the three trees model (it is redundant with
the new Noted document).