Fix of default category name when creating a new element instead of showing zero

When you are creating a new element in default is selected category 0 but correct text should be None (for English).

**Example for Chunk**
Before:
![-screenshot-11 10 2014 22_39_24](https://cloud.githubusercontent.com/assets/378835/4604109/863fecd4-5187-11e4-8f44-3604c55e92dd.png)

After:
![-screenshot-11 10 2014 22_40_00](https://cloud.githubusercontent.com/assets/378835/4604110/8ab873f8-5187-11e4-91f8-3ebc508cf400.png)