Merge remote-tracking branch 'origin/feature/5627_remove_loadraw_V1andV2'
Redraw picking image in DrawMode. Re #6624.
Merge remote-tracking branch 'origin/feature/6624_bug_masking_pixels'
Merge remote-tracking branch 'origin/feature/5627_remove_loadraw_V1andV2'
Re #6738. Only create listener if the alg doesn't already 'have' one.
Re #6738. Enable use of multiple FileEventDataListeners at same time.
Re #6738. Documentation correction that didn't merit its own ticket.
Merge branch 'feature/6738_create_fewer_livelisteners' into develop