Create thumbnails for about page

Made thumbnail versions of the pictures on the About page to improve loading performance. The original photos are still there in case you want to use the bigger versions in a lightbox or something.
![screenshot 2014-08-24 18 52 01](https://cloud.githubusercontent.com/assets/357896/4024938/bae62f28-2be1-11e4-9289-0e879e80afb7.png)