Merge branch 'customization' into integration

Conflicts:
	pom.xml
	src/main/java/de/thm/arsnova/controller/LoginController.java
	src/main/java/de/thm/arsnova/dao/CouchDBDao.java
	src/main/java/de/thm/arsnova/services/SessionService.java
	src/main/java/de/thm/arsnova/services/StatisticsService.java
	src/main/java/de/thm/arsnova/socket/ARSnovaSocketIOServer.java
	src/main/webapp/WEB-INF/spring/arsnova-servlet.xml
	src/main/webapp/WEB-INF/spring/spring-main.xml
	src/main/webapp/WEB-INF/spring/spring-security.xml
	src/main/webapp/arsnova.properties.example
	src/test/resources/arsnova.properties.example