Added material support to ellipse.
Work to understand texturing in WPF.
Save bug fixes

- App wasn't asking to save on exit with a new or existing file.
- On Save As edit count wasn't being cleared.
Throttle property changed events.

New to reactive, but it seems to be doing what I want.
Added timing to resource manager.

Added ability in TimedBlock to get elapsed time after the timer has been
stopped.