Various fixes for NTK.

Icon buttons before:
![1417600525](https://cloud.githubusercontent.com/assets/708296/5313447/5e15a204-7c60-11e4-956a-c9972ada64fd.png)

... and after:
![1417600512](https://cloud.githubusercontent.com/assets/708296/5313450/61db9c4a-7c60-11e4-80af-c7f5558e3696.png)