started adapting client and server to new database model

src/de/deadlocker8/budgetmaster/logic/NormalPayment.java

src/de/deadlocker8/budgetmaster/logic/Payment.java

src/de/deadlocker8/budgetmaster/logic/RepeatingPayment.java

...deadlocker8/budgetmaster/logic/RepeatingPaymentEntry.java

src/de/deadlocker8/budgetmaster/logic/ServerConnection.java

src/de/deadlocker8/budgetmaster/ui/Controller.java

src/de/deadlocker8/budgetmaster/ui/NewPaymentController.java

src/de/deadlocker8/budgetmaster/ui/PaymentController.java

src/de/deadlocker8/budgetmaster/ui/cells/PaymentCell.java

.../deadlocker8/budgetmasterserver/main/DatabaseHandler.java

src/de/deadlocker8/budgetmasterserver/main/Main.java

...de/deadlocker8/budgetmasterserver/server/SparkServer.java