[stella] Another suggestion for Stella emulator

[Dennis Debro]

Hi there,

It would be nice to have a record function. I could help track down bugs.
For instance, we could record game play in the emulator. Later we could
load that recorded playback in the emulator and step through the debugger
to find bugs.

This would help in trying to trace down bugs on a frame bases. Sometimes
the display is already up showing the bug and we don't know what caused
it. Having the game recorded would allow us to stop at the frame before
the problem and see what is happening.

Take care,
Dennis