rofiles: Add --copyup option

rofiles: Add --copyup option

Sadly https://sourceware.org/bugzilla/show_bug.cgi?id=22089 is I think going to
actually force us to cave here. Even if we got the glibc patch in today, we need
to support the RHEL glibc. See also discussion about fish as part of the general
Fedora tracker.

This is basically needed to unblock rpm-ostree unified core 🌐:
https://github.com/projectatomic/rpm-ostree/issues/729

Closes: https://github.com/ostreedev/ostree/issues/1377
Closes: #1382
Approved by: jlebon