DNT indicator. Resolves  #2371

DNT indicator looks like:
![dnt indicator](https://cloud.githubusercontent.com/assets/592286/3031717/c9d91bfe-e04f-11e3-956d-1e6564012e46.png)

It's description looks like:
![dnt description](https://cloud.githubusercontent.com/assets/592286/3031726/d222b69e-e04f-11e3-910a-b8bdb39bf4f0.png)

Resolves #2371