Asterisks in link titles aren't handled correctly.

[krisajenkins]

This markdown works as you'd expect:

[Brainfuck](https://en.wikipedia.org/wiki/Brainfuck)

...but if you want to be polite about it, then you're out of luck, because this markdown:

[Brainf*ck](https://en.wikipedia.org/wiki/Brainfuck)

...parses as Str "[Brainf*ck](https://en.wikipedia.org/wiki/Brainfuck)".

I tried the same markup in http://spec.commonmark.org/dingus/ and it renders as a link, so I believe it's valid markdown.

Thought you'd want to know. :-)

[garyb]

Thanks for the report!