Added AccountServices class to get balance information about the account (needs a better replacement).
Modified BaseUI to show current balance
Modified ExpenseRepository to get the total ammount of expenses.
Modified IncomeRepository to get the total ammount of incomes

1110863 | 1110328
Merge branch 'master' of https://github.com/PauloGandraSousa/EAPLI_2013_PL_2DI