feature suggestion: Render commands as 2D barcode

[mofosyne]

Been trying out a desktop QR code scanner and been thinking... it might be worth exploring being able to display the command as a QR code rather than typing it out manually.

[Anonymous3-a]

Except for the GNU/Linux smartphones, I don't think that it would be very helpful (think about it, when was the last time you scanned a qr code with your computer?). If you have time, I'm sure the pull request would be merged though.