VIC timing bugs

So this is easiest to see if you run the following in console, having built up to a decent per-click value:

```
CClicker.loadDisk('/rom/truth.d64');
setInterval(function(){$('#click').click()},3)
```

Notice how, once loaded and running, the `64 #1` moves in a jerky and jumpy fashion. Compare to the same disk image running in VICE.
