use the address of the device structure for device selection in usb_open instead of the device number

git-svn-id: https://svn.code.sf.net/p/libusbjava/code/trunk@266 94ad28fe-ef68-46b1-9651-e7ae4fcf1c4c

java/src/ch/ntb/usb/Usb_Device.java

@@ -31,6 +31,13 @@ public class Usb_Device {
 
 	private Usb_Device children;
 
+	/**
+	 * The address of the device structure to be passed to usb_open. This value
+	 * is used only internally so we don't use getter or setter methods.
+	 */
+	@SuppressWarnings("unused")
+	public long devStructAddr;
+
 	/**
 	 * Returns the reference to the bus to which this device is connected.<br>
 	 *