Create ability for emu86 to "poke out" values

[hintron]

It would be nice if there was an emu86 command that could "poke" a value out of the emulator to a file or stdout or something. This would enable emu86 to talk to regression tests directly.

I'm envisioning a way to set up regressions for simptris on various seeds, run each of them until Game Over, and confirm that the correct score has been reached.

Note that the "score" variable currently doesn't match the score inside the simptris emulator. So I would also want a way to get that real value from the emulator itself.