Integration of external picture file optimizer (Pingo)

[masterjp]

I usually compress jpeg and png files with pingo optimizer (https://css-ig.net/pingo) to compress jpeg/png files to the smallest size.
The results of png files are impressive. If you use jpeg files it will only saves 1-30 percent.
the pingo optimizer saves jpeg files in another way and remove exif data.
The optimization ist very fast (multi cpu core support).

It would be nice to see such a feature in XnViewMP in the future.

The Riot Plugin (http://luci.criosweb.ro/riot/screenshots/) has a good implementation for external optimizer.
You choose the optimizer file (*.exe) and can set the parameters. The plugin only works with xnview (32 bit),
but is not compatible with XnViewMP.