Display Node Image

Many of my nodes have an image attribute (imported from graphviz) with a URL to an image that represents the node. I would be thrilled if a partition option or general option were available to render those images in the main window. I admit this is a long shot -- I can see a lot of caveats such as bandwidth etc. -- but I figure it would be good to put this out there! Since a lot of these URLs are relative, it would be nice to be able to set a base URL.

The issue names no files, tests, or entry points. Begin by locating node rendering and graphviz image-attribute handling, then define how a partition or general option and a base URL should work; done would mean node images render in the main window, including relative URLs.

Written by the indexing model from the issue text.