The tarball can be copied to the VM through the serial port with the
following command:
# cat > mumble-vm.tar.xz.b64
the user then pastes the base64 content and types ctrl+d and this
results in the file being written.
The content can then be extracted with the following commands:
# base64 -d mumble-vm.tar.xz.b64 > mumble-vm.tar.xz
# tar xf mumble-vm.tar.xz
Signed-off-by: Denis 'GNUtoo' Carikli <GNUtoo@cyberdimension.org>