Enhc volunteer section

Volunteer image with new mask class

Simple class to create a rounded clipping mask for content or an
image.

Decided not to use "clip-path" css property because its not widely
supported.

Uploaded this image myself.

Other changes:
- Setup radial progress bar to be ready for development.

![screen shot 2014-11-06 at 3 39 35 pm](https://cloud.githubusercontent.com/assets/1701077/4946029/d8b5db40-660e-11e4-92b5-b51ba87e971a.png)