Fixes #703 dist/ramda.js does not contain comments

I'd prefer to see this written with fewer variables. Something along these lines:

```javascript
var comments = [];
var tokens = [];
return {
    ast: acorn.parse(fs.readFileSync(filename), {
        ranges: true,
        onComment: comments,
        onToken: tokens
    }),
    comments: comments,
    tokens: tokens
};
```

I'm surprised that `acorn.parse` mutates the arrays provided. That's not in the spirit of Ramda, of course. ;)