Add payment form for the backend.
Fix usage of $_POST variable inside the payment model.
Add usage of credit card for the backend (without tokenization).
Remove duplicated credit cards.
Add PHPDoc for the 'Storedcard' model.
Add support for custom error message. Fix exceptions handling.
Fix HTML of the frontend payment form.
Add modman file.
Correct casing.
Add a new method to throw a user error message.
Fix POSGATEWAY class.
Fix 'transactions_lib.php' file.
Add voiding payment feature.
Merge pull request #16 from sergeykalenyuk/fixes

Improvements