notification shit
Merge remote-tracking branch 'origin/master'

Conflicts:
	ch.bfh.bti7081.s2013.yellow/src/main/java/ch/bfh/bti7081/s2013/yellow/model/notification/Notification.java
	ch.bfh.bti7081.s2013.yellow/src/main/java/ch/bfh/bti7081/s2013/yellow/service/notification/NotificationServiceImpl.java