Simplify Rendering Framework

In talking to Jesse the areas where rendering are complicated boils down to...

Limit EMF use to Data Model

• The use of EObject in the execution model (RenderCreator and RenderExecutor) is not needed.
• We can restrict the use of EObject to where it pays off (where user interaction is involved).
• Actions: limit EMF use to Map / Viewport / Layer / Page / Box

Use a "command queue" rather than events.

• use of events use of events to pass control information (this results in an amazing number of opportunities to screw up and miss out on refreshing the screen).
• since we need to bounce between multiple rendering threads and the single display thread we have even more opportunities to freeze the screen!
• we should switch to a command queue style of interaction (as was done for arcsde)