Merged the digital IO and Echeque IO classes
Removed digital certificateIO from bank side
Refactored Digital certificate and Echeque classes
Fixed bugs and refactoring for digital certificate and Echeque classes
Fixed bugs and refactoring for digital certificate and Echeque classes, forgot to add server side
Merge branch 'master' into Mac

Conflicts:
	The e-Cheque Client/src/eCheque/Echqueserver.java
	e-Cheque Bank Side/src/eCheque/EChequeDB.java
	e-Cheque Bank Side/src/eCheque/Echqueserver.java
Merge branch 'Mac'