Add more bio information on post

Added author image on main page. 
![index](https://f.cloud.github.com/assets/866514/1630553/f7da837a-574d-11e3-876a-3564cd2692bd.jpg)


More about author bio on post page.
![post-bio](https://f.cloud.github.com/assets/866514/1630548/cdd89ac6-574d-11e3-98f6-11b692620d19.jpg)