This avoids exporting glnx_*, calc_sizes(), etc. However, we do want to
export xdg_app_error_quark(), so do that.
Signed-off-by: Simon McVittie <smcv@debian.org>
We now check at runtime if we have raised privs, and only if not so do we try
to use unprivileged user namespaces. This means you can build xdg-app however,
and then setuid/setcap the binary however you want afterwards.