While qvm-move and qvm-copy cannot work in dom0, their
absence is confusing. Thus, stub tools that output message
informing the user that these tools are unavailable and
qvm-move-to-vm/qvm-copy-to-vm should be used instead.
fixesQubesOS/qubes-issues#4021
#!/bin/bash because qvm-move-to-vm sources qvm-copy-to-vm, which has
a bashism (-o pipefail).
&& is safer in case qvm-*copy*-to-vm is ever changed to call 'set +e'.