Merge devel0.6 into newui

[Libor Polčák]

Hello Giorgio,

I merged devel0.6 branch into newui on pagure. I manually tested conflict and 
it seems to me that they are resolved correctly. But if the NBS and FPD sliders 
behave strangely or there is a renamed element, it is likely due to the 
merge/conflicts. Let me know if I messed something.

Anyway I would rather to move swiftly to merge the new UI into the master. Is 
there any progress with 
https://lists.nongnu.org/archive/html/js-shield/2021-12/msg00001.html? Let's 
discuss on the meeting.

Best

Libor