Added DeveloperFlagsEnum. Each enum value in DeveloperFlagsEnum has an...

Added DeveloperFlagsEnum.  Each enum value in DeveloperFlagsEnum has an associated true/false value (static methods to set/get) that is used to enable/disable functionality during software development and testing.  Each enum value is automatically displayed in the Developer Menu where its true/false status can be toggled.  After a flag is toggled via the GUI, all surface coloring is invalidated, the user interface is updated, and all graphics windows are redrawn