fixed issue #12
corrected constructor method on Expense class
asking for correct information about payment methods

1110998 Marcel Schmitz
1111224 Luís Ferreira
fixed issue #11
register payment with cash

1110998 Marcel Schmitz
1111224 Luís Ferreira
Merge branch 'master' of https://github.com/PauloGandraSousa/EAPLI_2013_PL_2DI.git