Not correct parse srcset

Hi,
Not correct parsing srcset in img tag
Example:

```
<img src="http://example.com/prev4-45x45.jpg" srcset="http://example.com/prev4-150x150.jpg 150w, http://example.com/prev4-45x45.jpg 45w" sizes="(max-width: 45px) 100vw, 45px" width="45" height="45">
```

Please, make option for convert all other links from relative to absolute.
Thank you
