Removing setters where not needed
Merge origin/master

Conflicts:
	modules/service/src/main/java/ch/bfh/uniboard/service/ByteArrayValue.java
	modules/service/src/main/java/ch/bfh/uniboard/service/DateValue.java
	modules/service/src/main/java/ch/bfh/uniboard/service/DoubleValue.java
	modules/service/src/main/java/ch/bfh/uniboard/service/IntegerValue.java
	modules/service/src/main/java/ch/bfh/uniboard/service/StringValue.java