javascript fenced code block parsing error

use extras = ['fenced-code-block']. when fenced code block is javascript, markdown2 parses some md5 strings..

for example:

	```javascript
	<script type="text/javascript" src="{{ static_url('shadowbox/shadowbox.js') }}">
	</script>
	<script type="text/javascript">
	Shadowbox.init({ handleOversize: "drag" });
	window.onload = function() {
	    Shadowbox.setup(".entry-content img", { gallery: "{{post.title}}", counterType: "skip" });
	};
	</script>
	```

is parsed to:

    <div class="codehilite"><pre><code><span class="nx">md5</span><span class="o">-</span><span class="mi">26</span><span class="nx">a31e11f9061693a9bf87e6a0855ef5</span>


the right result should be:

```javascript
<script type="text/javascript" src="{{ static_url('shadowbox/shadowbox.js') }}">
</script>
<script type="text/javascript">
Shadowbox.init({ handleOversize: "drag" });
window.onload = function() {
    Shadowbox.setup(".entry-content img", { gallery: "{{post.title}}", counterType: "skip" });
};
</script>
```