Run VICE-based tests under Windows

[jdpage]

PR #59 introduced a harness for testing gold-syntax programs by running them under VICE. As written, this uses the pty module, meaning that it doesn't work under Windows. It would be nice if we these tests could also be run under Windows.

There may be other issues, besides the pty issue. In particular, I don't know if WinVICE connects its monitor to stdout/stdin. Of course, the remote monitor might actually work under WinVICE, in which case we can just talk to it over a socket.

[jdpage]

WinVICE does not connect its monitor to stdio, but the remote monitor at least doesn't crash immediately. However, using it under PuTTY doesn't seem to work--it'll accept commands but not run them. I don't know if this is weirdness with PuTTY or the VICE monitor broke. It's clear that it worked at some point, because this project from a couple years ago used it.