[a](b) links shouldn't expand inside of a code block

[jdanbrown]

From this:

```
foo[Int](3) == bar
```

I get:

foo[Int](http://3) == bar

[adam-p]

This is a result of the fix for issue #57. Ugh. Every time I mess around with pre-parsing Markdown it creates a whole bunch more bugs.

The cleanest way of doing this right would be if Marked.js had a hook for customizing inline elements (markedjs/marked#105). As it is, our copy of marked.js will probably have to be further modified.

Note to self: Add a test case for this.

[adam-p]

Fixed in development branch. Will be in next release.