Merge commit 'refs/merge-requests/6' of git://scm.thm.de/arsnova/arsnova-war into merge-requests/6

Conflicts:
	src/main/java/de/thm/arsnova/controller/SessionController.java
	src/main/java/de/thm/arsnova/dao/CouchDBDao.java
	src/main/java/de/thm/arsnova/dao/IDatabaseDao.java
	src/main/java/de/thm/arsnova/services/ISessionService.java
	src/main/java/de/thm/arsnova/services/SessionService.java
	src/test/java/de/thm/arsnova/dao/StubDatabaseDao.java