In fact the entire void implementation needs changing.

The standard AM interface is to have a single #void method specified as `def void(identification)`.

Please do the following instead:

* Remove the `void_auth` method.
* Remove the commented out `void_capture`, `void_sale`, `void_refund` methods.
* Correct this method signature to match the ActiveMerchant standard.
* Move this method UP the file to be above the `private` line to make it public.
* Adjust this method to perform a **VOID_AUTH** API action only.
  * This would be the standard behaviour that I would expect from calling #void on a gateway.

Explanation: CommerceGate gateway's additional VOID_CAPTURE, VOID_SALE, and VOID_REFUND API methods will not be used, because as a) they are only time-sensitive temporary dependant on the state of the transaction, b) the API does not appear to offer any way to query the state of the transaction, c) if you auth+capture then want to "undo" after capture, the standard AM behaviour would be to issue a subsequent refund.