Image inside a link produces invalid HTML in preview

[jjok]

Also, the URLs for the image source and the link are the wrong way round.

[![alt text](http://example.com/image.png)](http://example.com)

Produces:

<p><a href="http://example.com/image.png"><img src="http://example.com" alt="alt text</a>" /></p>

Should be:

    <p><a href="http://example.com"><img src="http://example.com/image.png" alt="alt text" /></a></p>

[jjok]

Maybe #25 ?