As rpm-ostree evolves, it keeps driving API additions to libostree.
This creates a relatively tight coupling.
However, if delivering via e.g. RPM, unless one manually remembers to
increment the `Requires:` in the spec file, it's possible for the two
to become desynchronized.
RPM handles versioned symbols and will ensure a dependency if the
application starts using a newer version.
To implement this, switch to `-fvisibility=hidden`, along with an
annotation in the header, and finally add a `.sym` file.
This matches what other projects like systemd and libvirt do.
Although rather than attempting to retroactively version symbols, glom
them all onto the current one.
We want an OstreeRepoFile to be the way to represent a filesystem tree
inside an ostree repository. In order to do this, we need to drop the
commit from an OstreeRepoFile, and make that go to callers.
Switch all current users of ostree_repo_file_new_root to
ostree_repo_read_commit, and make the actual constructor private.
https://bugzilla.gnome.org/show_bug.cgi?id=707727
Instead, use OstreeRepoFile as a handle for the parent commit.
We need to add an accessor for the metadata checksum, as that
hasn't been exposed before.
https://bugzilla.gnome.org/show_bug.cgi?id=707727