Maximize the viewable screen for Models

Firstly, thanks very much for all the improvements on models. I provided some input to these changes, and we started using them the day they were released. Thanks again. 

Small improvement - Make the space on the left collapsible where the list of models is displayed. While brevity in the development of these models is important. There really is no need to show all the models all the time. If you could collapse this area of the total page you would reclaim about 10% of the total active display.  This change will keep more of the text above the fold in the models display and edit.