Get haml to pass syntax check.

You can check the syntax with `haml -c [file.haml]`.  Most of the errors were from the indentation being off&mdash;as far as `haml` is concerned, all the tumblr blocks are just plain text, and therefore shouldn't be nested as you might an element.

I renamed one &lt;div&gt; and added a couple more, to get what seems like a consistent structure (to me, at least):

![structure](https://cloud.githubusercontent.com/assets/5863302/5332161/058a3174-7e11-11e4-9a73-fb7256bb0fcd.jpg)

And, personally, I recommend heavy use of the filters in `haml`, e.g., `:javascript`. (I used `:markdown` fairly often myownself in `tawp`.)