Splitted state machine tests into smaller units
Implemented commit of the transaction
Merge branch 'master' of github.com:sbaechler/ParkingMeter

Conflicts:
	src/main/java/ch/zhaw/id5848/parkingmeter/core/Printer.java
	src/main/java/ch/zhaw/id5848/parkingmeter/core/TicketPrinter.java
	src/main/java/ch/zhaw/id5848/parkingmeter/core/states/ParkingRegisteredState.java
	src/test/java/ch/zhaw/id5848/parkingmeter/core/ParkingMeterControllerTest.java
Added missing TODO