Fix close button spacing and positioning

Fixes #9

This also moves the image close button over to the *right* of the image, as in Linkinius.

![screen shot 2014-10-24 at 11 49 04 am](https://cloud.githubusercontent.com/assets/168193/4775043/c0ec2c04-5bb3-11e4-80e7-3f4da2f2a327.png)