Automatic processing of all Narrowband palettes

A new narrowband palette option All automatically processes all HSO palettes it knows. Every image is named with the palette option and automatically saved to disk as a .xisf file. Images are also left open on screen. With Save batch result files selection it is possible to save them all for example as 16 bit TIFF files.

You can also use extra options in images, then images with name Auto_+palette-name+_extra are created.