Weird entity code in markdown footnotes

[Jaymon]

In a test, if you create a page:

 p = self.get_page([
            "before",
            "",
            'footnote[^1]',
            "",
            "after",
            "",
            "[^1]: http://example.com foo",
        ])

And then get the html using p.html, you get this html:

    <p>before</p>
    <p>footnote<sup id="fnref-3-1"><a class="footnote-ref" href="#fn-3-1">1</a></sup></p>
    <p>after</p>
    <div class="footnote">
    <hr>
    <ol>
    <li id="fn-3-1">
    <p><a class="embed" href="http://example.com&#160">http://example.com&#160</a>;<a class="footnote-backref" href="#fnref-3-1" title="Jump back to footnote 1 in the text">&#8617;</a></p>
    </li>
    </ol>
    </div>

Notice the a tag:

<a class="embed" href="http://example.com&#160">http://example.com&#160</a>

The footnotes plugin is placing &#160 (which is the   entity) on the footnote and then the linkify embed plugin is picking that up and putting it into the auto generated url, it's not the end of the world but it's weird it's doing that.

I've traced this back to the builtin markdown footnotes code (not Bang's code), but I don't know why it is putting &#160 at the end of the footnote.

The first thing I'm going to do is update to the latest version of markdown.