Fix action bar title update problem

### Main Activity 
- There is (was) a problem with the title when switching content from **Folders** to any other content.
- Close left drawer when back button is pressed instead of ending activity


![screenshot_2014-09-28-12-34-21](https://cloud.githubusercontent.com/assets/2534772/4433921/95f3d00a-46f6-11e4-8f4f-0d001cc2f4ed.png)