TLShell gpg signature indicator

[Petr Krajník]

Hi, I would like to see the status of the gpg signature check in 
TLShell. If gpg is present on that particular machine. In the old GUI 
that was a label after the path. In the cmdline interface this also 
works well as in tl2018.

It would give a nice feeling of safety if it would be also show in the 
TLShell. Especially if it would be highlighted by color (green verified 
or similar).

Or is this feature implemented and I only don't see it? Anyway I think 
this is a must have and should be implemented!

Thank you.

Best regards
Petr Krajník