Fixed #57 - disable editing of payment rest

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

@@ -66,9 +66,13 @@ public class PaymentController implements Refreshable
 						if(event.getClickCount() == 2)
 						{
 							PaymentCell c = (PaymentCell)event.getSource();
+							//don't allow editing of payment "rest"
+							if(c.getItem().getCategoryID() != 2)
+							{
 								payment(!c.getItem().isIncome(), true, c.getItem());
 							}
 						}
+					}
 				});
 				return cell;
 			}