Implement developers helper

Features:
Display definitions/notes in a intuitive interface
Edit and save fields without open the .json file
Add/edit definitions/sites
Create new language
Show only incomplete translations

![catt](https://f.cloud.github.com/assets/1665768/1078720/b10f956a-1531-11e3-834c-3acb263f820b.PNG)
![catt2](https://f.cloud.github.com/assets/1665768/1078721/b1306d6c-1531-11e3-9dd5-200a40ee1e9f.PNG)