New icon sizes added

Hey man. Great work on this, saved me some pain. I added some sizes that I couldn't fill with the defaults:

![screen shot 2014-11-04 at 13 30 42](https://cloud.githubusercontent.com/assets/1426233/4900548/6f1bfbf2-6428-11e4-8fef-883774821be6.png)

Merge if you wants.