The current reference images docker has problems:
* the images are not saved with the kra document, so you cannot have a set of references associated with your document
* if there's an image a QImageIO plugin crashes on in the current folder for the reference images docker, krita crashes on startup
* the file management sucks
* zooming and panning doesn't work like on the canvas
* the image is constrained to a docker, so it isn't shown near where you want to draw
I propose to replace the docker with a reference images tool. The tool would manage reference images places on the workspace. Reference images (or filesnames) would be saved with the .kra file.
* Dropping an image on the canvas would add an extra option to the drop menu (add as reference image)
* The tool would allow
** adding images
** moving images
** scaling images
** rotating images
** removing images
* Krita should save the images with the document. The user should be able to select to save the image itself in the .kra file, or a file path. Images can be placed anywhere on the workspace, relative to the image, so the gray area outside the image is usable as well.
* The color picker should pick colors from the reference images