Instead of using 'pi' as default, try to get the username of
the current user from the OS.
May not always work. (e.g. some Windows users may not have
setup a username themselves, but may be using a default user
created by the PC vendor).
Closes#497
Just feed them through the libarchive workflow as well.
Prevents issues on Windows/osx when writing uncompressed images
that come from the Internet.
Ref #473
Only supported when NetworkManager is used on the Linux distro
as wpa_supplicant itself does not support reading PSKs through
DBus, only setting them.
Closes#457
