Translate en.yml to dutch
Translate devise.en.yml to dutch

Based on https://gist.github.com/JanDintel/5424640
Update nl.yml
Update devise.nl.yml
Translate controller strings to dutch
Merge branch 'pr/799'

* pr/799:
  Translate controller strings to dutch
  Update devise.nl.yml
  Update nl.yml
  Translate devise.en.yml to dutch
  Translate en.yml to dutch