Created Main stage and content area. 
Created CSS file.
Imported InsideFX Undecorator for styling the Main stage.
Application is now prepared to use the FXMLLoader to place content into the Main content area.
Changed the background of the main content area.

Added method to apply event handlers to toggle buttons in the Main anchorpane.

Will throw and error because packages for course, employee, and vehicle have not yet been added.