Mummify notification system with progress indication.
With long-running image processing in GUISE-177, it is often difficult to know the progress of mummification when e.g. 25 images are being scaled. It would be nice to know at minimum the name of an artifact taking a while to be mummified. Even nice would be an overall progress of site mummification.
Create a notification system where ever artifact, via the MummyContext, reports back some event (e.g. "mummify begin", "mummify end") and perhaps even a progress if known (or if knowable; this may not be useful for may cases). The main Guise Mummyprogram could have some sort of timer it starts at the beginning of mummification for each artifact (each corporeal artifact—not directories) and have a way to output some message if mummification of a single artifact is taking too long. This central notification manager could emit the overall progress of mummification as well.
The solution needs to be multithreaded aware, because eventually we will want to turn on multithreaded, concurrent mummification.