Windows support

[meh]

Add support for Windows.

This would imply a new thingy to handle the tty, I assume, and wrapping the Cairo Win32 bullshit, but that shouldn't be too hard.

I'm a little concerned about the current event driven design where the handling is actually in main, and the window is a separate thing in a different thread, I'm not sure how that works out, I might have to change that too, but shouldn't be too hard.