Merging frontend-testing into master

See merge request !43

# Conflicts:
#	src/main/java/no/ntnu/idatt1002/demo/controller/BudgetController.java
#	src/main/java/no/ntnu/idatt1002/demo/controller/FinanceController.java
#	src/main/java/no/ntnu/idatt1002/demo/controller/IncomeExpenseController.java
#	src/main/java/no/ntnu/idatt1002/demo/controller/MainMenu.java
#	src/main/java/no/ntnu/idatt1002/demo/controller/SceneController.java
#	src/main/java/no/ntnu/idatt1002/demo/data/Budget/GeneralBudget.java
#	src/main/resources/Budget/Budget.budget
#	src/main/resources/Economics/Expense.register
#	src/main/resources/Economics/Income.register
#	src/main/resources/view/BudgetNewest.fxml
#	src/main/resources/view/IncomeAndExpenses.fxml
#	src/main/resources/view/MainMenuNew.fxml
#	src/main/resources/view/dualList.fxml
#	src/main/resources/view/newBudgetBudgert.fxml
#	src/test/java/no/ntnu/idatt1002/demo/data/Budget/GeneralBudgetTest.java

Hs frontend recipes

See merge request !42

# Conflicts:
#   src/main/resources/Economics/Income.register

Implemented new button to distinguish button that returns to main menu, and button that returns to start

Changed the method caller class from FileHandlingBudget to FileHandlingBudgetArchive or FileHandlingSelectedBudget that are responsible for these methods