Add .gitignore file. fix problem in my previous commit

Hi.
- Delete binary file in the repo
- in css, background attribute is changed.
- admin folder remove

Hopefully, everything is okay :)

![vibelog-new-admin-menu](https://cloud.githubusercontent.com/assets/1070077/4020902/5efb46b2-2ad8-11e4-97e5-80fba0d23ba1.png)