Line up facebook share and tweet buttons.

The main problem was the Facebook iframe had a fixed height and width. I fixed the height using specifications on the iframe as shown in some of the code on Facebook [here](https://developers.facebook.com/docs/plugins/like-button), and fixed the width using a script as suggested [here.](http://stackoverflow.com/questions/7494021/facebook-like-button-iframe-too-wide)

Then I put the buttons in a column copied from the column spec for the music embed, and used the pull-right and pull-left classes to make the buttons line up with the outside edge of the music embed. It might look a little better if they were inset slightly --- if you want to try that you could add margins on the buttons or wrap them in a div with some padding. 

I changed some of the indentation at the beginning so I could see the structure of the divs a little better, and added more comments for the \</div\>'s.

[Take a look.](http://chetstone.github.io)