[cleanup] made method generic to avoid casts
[cleanup] removed superfluous method
[cleanup] removed instance-of test
[fix] replaced the wrong with the right variable name

Conflicts:
	registration-module/src/main/java/org/osiam/web/controller/ChangeEmailController.java
[cleanup] formatted code & organized imports
Conflicts:
	registration-module/src/main/java/org/osiam/web/controller/ChangeEmailController.java
	registration-module/src/main/java/org/osiam/web/controller/LostPasswordController.java
	registration-module/src/main/java/org/osiam/web/controller/RegisterController.java
[cleanup] did some things mentioned in the comments of #90:

- removed useless comments
- fixed some typos
Conflicts:
	registration-module/src/main/java/org/osiam/web/controller/ChangeEmailController.java
	registration-module/src/main/java/org/osiam/web/controller/LostPasswordController.java
	registration-module/src/main/java/org/osiam/web/controller/RegisterController.java
[fix] fixed BT-28
[fix] fixed BT-28 for confirm endpoint
[fix] fixed BT-27
Merge pull request #115 from tkrille/BT-27_BT-28

Fixed BT-27 and BT-28