sulu-cmf/sulu-standard#125 Copy locale ui

__Tasks:__

- [x] test coverage
- [ ] gather feedback for my changes

__Informations:__

| Q             | A
| ------------- | ---
| Tests pass?   | yes
| Fixed tickets | sulu-cmf/sulu-standard#125
| BC Breaks     | none
| Doc           | none
Just an idea: wouldn't it make sense to do this in the Backbone model?