Added support for getting returned checks via date range for all gateways.
Still some remaining questions as far as how it will work for Auth.NET and TransNational, but put our best guess in for now.
Nothing in our system calls these methods yet, but when they do this functionality will be already there and ready to go.
Merge branch 'TransactionGateway' of https://github.com/bvcms/bvcms into TransactionGateway