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.
Several APIs in libostree were moved there from the commandline code,
and have hardcoded g_print() for progress and notifications. This
isn't useful for people who want to write PackageKit backends, custom
GUIs and the like.
From what I can tell, there isn't really a winning precedent in GLib
for progress notifications.
PackageKit has the model where the source has GObject properties that
change as async ops execute, which isn't bad...but I'd like something
a bit more general where say you can have multiple outstanding async
ops and sensibly track their state.
So, OstreeAsyncProgress is basically a threadsafe property bag with a
change notification signal.
Use this new API to move the GSConsole usage (i.e. g_print()) out from
libostree/ and into ostree/.