Feature icons

I have added colors and colored icons, here there are 2 example,
With icons:
![ref-icons](https://f.cloud.github.com/assets/4006972/1423245/b63b28a0-4007-11e3-8b33-c928e3ab9cae.png)
Only with colors:
![color-example](https://f.cloud.github.com/assets/4006972/1423254/d7ee0bac-4007-11e3-90d8-341545072d52.png)

Colors are the same (insipred) by original gitweb colors. I'm open for some modifications, or is simple to remove the icons.