Resets the queue of files to be transferred.
This method will remove all files from the transfer queue.
Calling this method will clear all files that were queued by QueueFile. Calling this method will not affect current transfers.
This method returns a result code; 0 indicates success, while a non-zero error code indicates that this method encountered an error during its execution. If an error occurs, the GetLastError() method can be called to retrieve the associated error message. (Note: This method's result code can also be obtained by calling the GetLastErrorCode() method after it returns.)