Entity preservation

HTML Entities inside a truncated text node are decoded, resulting in possibly invalid html or xss vectors.

This path preserves all entities, a unwanted side effect could be that

```
// ...
ellipsis: "<a href='#'>more</a>"
// ...
```

will be escaped, too, because the node in operation is a simple text node.

A possible workaround would be to insert a ellipsis node of some sort after the truncated text node and setting the ellipsis via .html(o.ellipsis)