Option for batch processing window

[vitar]

I suggest to add the option "Open output directory after processing completed" with two 'sub-options': open it in XnView or as a window. Example of usage: I convert images for sending them by email (local client), and this option would greatly improve the usability: no need for browsing in order to open the folder with converted pictures. Opening directly in XnView means that I am not going to work more with the files in the original directory; othervise opening as a window will be more convenient.