Added "Menage Newsletters" with preview, create and delete possibilities

Added functionality to "Preview Newsletter", now "Newsletters".
Create in archive now implements Id control.
Below is a screenshot for the new look.

![Image 2](https://f.cloud.github.com/assets/628801/143587/73e464b8-73b5-11e2-87b6-9e4acec20708.png)