Fix unattached speeches CSS bugs

I've added masonry to the required page, which fixes the grid issues.

And I've made a new `standalone="1"` option for the `speeches/speech.html` template, which lets you disable the speaker avatar and left-hand vertical line for speeches which you *know* aren't meant to be attached to the speeches above or below them.

![screen shot 2014-05-08 at 18 00 25](https://cloud.githubusercontent.com/assets/739624/2918632/4aa53132-d6d2-11e3-8f53-7e68fd571323.png)