Remember last location in dialogs

[ctgnz]

The dialogs to select images or overlays should remember the last location used, so that you don't have to navigate to the same location every time when you are processing multiple images from the same location. It would be okay, and probably preferred, for the base image and overlay image dialogs to remember different locations, as overlay icons are quite likely to be in a different place from the base images.

[jabiercoding]

Thanks. I label this as enhancement. In the meantime, just in case it was not noticed, users can select now multiple overlay (and base) images at the same time, and all the combinations can be saved at once.