Various footer fixes for mobile

Our old footer had CSS that was absolutely positioned, and that was pretty hard to position properly when changing the size of the screen changed. Now instead of `position: absolution`, we're just letting the height of the `tile__container` position the footer (and this is how it's done on the other tiles, too, like recipes).

![screen shot 2014-05-18 at 12 44 18 pm](https://cloud.githubusercontent.com/assets/81969/3008128/0aadf62e-deaf-11e3-8170-3079dd04579b.png)
![screen shot 2014-05-18 at 1 01 48 pm](https://cloud.githubusercontent.com/assets/81969/3008132/198b386e-deaf-11e3-9482-7c6e99656466.png)
![screen shot 2014-05-18 at 12 50 12 pm](https://cloud.githubusercontent.com/assets/81969/3008130/0aae18ac-deaf-11e3-9b4f-639ea979d9b0.png)