Altered the CDC Deivice and Host Class drivers' receive byte routines, so that no data is indicated by a negative return value.

Added auto flushing of OUT data to the CDC Host Class driver's USBTask function to automatically flush the send pipe buffer.

Demos/Device/ClassDriver/VirtualSerialMouse/VirtualSerialMouse.c

@@ -97,8 +97,7 @@ int main(void)
 		CheckJoystickMovement();
 		 
 		/* Must throw away unused bytes from the host, or it will lock up while waiting for the device */
-		while (CDC_Device_BytesReceived(&VirtualSerial_CDC_Interface))
-		  CDC_Device_ReceiveByte(&VirtualSerial_CDC_Interface);
+		CDC_Device_ReceiveByte(&VirtualSerial_CDC_Interface);
 
 		CDC_Device_USBTask(&VirtualSerial_CDC_Interface);
 		HID_Device_USBTask(&Mouse_HID_Interface);