Buffer implementation for makedrive

Same thing here, let's simplify:

I hate these deep loops.  Why not change it to something like this? (NOTE: I haven't tested this)

```javascript
function processDiff(diff) {
  if(diff.contents) {
    diff.contents.forEach(processDiff);
  } else {
    if(Buffer.isBuffer(diff.data)) {
      diff.data = new Buffer(diff.data);
    }
  }
}

diffs.forEach(processDiff);
```