How on earth does this work?

Urrgh, licensing.  I think for now I'd like to put this under boost, I have no idea if MPL is compatible.

This should do the trick, right?
```
char[] sx = s.dup;
foreach(ref char c; s)
    if (c >= 0x80)
        c = '?';
```

I don't really remember what this file does (some kind of primitive debugging aid), so it might be easier to just not build it.