Draft: Issue #9833: Add option to automatically scale imported layers to the canvas size
Attempts to resolve issue #9833.
This adds an option in Preferences to automatically scale images that are imported as layers to fit the existing canvas size.
The scaling code is adapted from @Ofnuts's ofn-autoscale-layer.py plug-in (linked in the original report). The scaling is done in file_open_layers () so that it works both for drag-and-drop as well as choosing "Open as layers..." from the menu.
An example of this behavior can be seen here: