Support multi-programming

[jas4711]

There should be a (possibly separate) tool to program multiple yubikeys at the same time. It could work by reading some input file with multiple configuration/keys/serials and when yubikeys are inserted it will personalize them. It should support having multiple yubikeys inserted at the same time.

/Simon

[klali]

With libusb it seems that we can use libusb_get_bus_number() and libusb_get_port_number() in combination to get a stable reference on where a device is plugged.

[klali]

On osX it looks like we can use the property kIOHIDLocationIDKey to track the location of a device. This can also be used for device matching.

[nbraud]

FYI, this is the subject of Debian bug #863041, and is blocking for the Debian Systems Administration team.

[klali]

Version 1.18.0 came with basic support for multiple keys, allowing the user to specify the number of the yubikey to be used.