Several improvements.

- Don't reuse created objects in tests
- UTF-8 encoding of workspace
- Mavenized
- New static analysis configuration
Replaced setVorname with a generic updateProperties method.
Added test case to verify all properties on save.
Make email first argument in all methods since it is the primary key.
Replaced findByEmail with findByPrimaryKey.

- Let getByPrimaryKey return a single object only. 
- A new containsEmail method helps to check for existing user name.