Modify(register.html): move FormCtrl declaration to the panel.
Fix(userform.tpl.html): fix regex pattern strings.
Modify(userForm.js): implement success and error methods of $http.post.

Refactor(UserService): rename to UserRegistrationService; change service url to '/user/register'.
Modify(UserRegistrationService): add Reply-ing on success and on UserNameExistsException.
Add(UserDTO).
Modify(userform.tpl.html): use ng-repeat to generate validated fields.
Modify(userForm.js): add 'formFields' factory.