Added rich text editor instead of markdown

Changed markdowns to rich text editor. 
Installed CKEditor as a rich text editor.
![screenshot from 2014-06-28 16 24 00](https://cloud.githubusercontent.com/assets/5913886/3421827/3b776dda-ff02-11e3-9fb1-f1724daec961.png)

Is it safe to remove this? We don't allow attachment options I think.