Worker-based "which file was added" watchdog for enabling non-standard mcplot output names

[willend]

Title kind of says it?

• To enable use of e.g. mcplot.pl with Giza backend, mcplot-matplotlib, ... whatever produces a png for embedding
• Hack to use the existing (hardcoded, PGPLOT-mcplot oriented) png filenames independent from what the plotter produces

[jakob-garde]

It looks like giza adds two files, *0000.png and *0001.png. On my system it claims to add a third file, but doesn't. The 0000 files don't show anything. I think we saw on the server that it only created a viewable file/something in the log case.

[jakob-garde]

The requested feature has been added by 838582b, now let's test and see if it can improve things somewhat - perhaps with a few modifications.

[jakob-garde]

The feature caused problems and should be fixed before it is used in release.

[jakob-garde]

The feature has been reverted as it seemed not helpful after all.