Wallet GUI

Group members: David Bohn, Luca Keidel, Fabian Reimeier, Friedrich Ueberreiter

We would like to fix the GUI of the wallets. As a first goal we plan to actually display the amount of FUCoins in the wallet as well as making the transaction log work. Further steps could include input validation, better error handling/feedback for the user and maybe a small restructuring of the GUI.