Add e-mail validator en change field name

Is there an e-mail validator already present? Also, we might need to consider to rename the field name to "Prename and name" as some people don't get it..

![schermopname 60](https://f.cloud.github.com/assets/3730236/2383826/6b04d470-a903-11e3-9aba-965b9585a943.png)

Screenshot taken from DN event.