gbe-442: user and groups management (backend)
GBE-442: corrections pull request: Add javadoc; add exception throw in AuthenticateUserCommand;add comments
GBE-442: typo's; remove unused ProfileAuthenticationService
Rename GetUSerResponse.java to GetUserResponse.java
Merge pull request #25 from geomajas/GBE-442_usersGroupsBackend

gbe-442: user and groups management (backend)