Refactored code that checks to see if the History directory is created
already or not, etc. It no longer intializes a new PrintWriter. Output
to the file is now done via an ObjectOutputStream. Added a onStartup
function that runs whenever the program is launched. This program loads
the objects in the file into the program into an ArrayList of
Transactions. This arraylist is then used by the
viewTransactionHistoryWindow to display the transactions. Added a
menuitem that allows the user to select a transaction to delete. Added
save function that writes all of the objects to the file.