imagefactory: Do conversion in correct place
create-vm-disk: Add --origin-url argument

For OS vendors who are ready to provide online updates out of the box
(without post-install configuration), this makes it easy to create a
VM image which has the origin URL hardcoded.
installer: Quote % to avoid interpretation as a format character

I didn't know Python argparse docstrings were actually formats.
cloud2ovf: Delete (it never worked, ImageFactory does)

ImageFactory does this better.
imagefactory: Log to stdout, not a file

The log file was getting deleted when the task finished even on error,
which was obviously annoying.  We can just print to stdout given that
we're running imagefactory synchronously anyways.
libqa: Add missing Format import

This only worked in older gjs versions due to a bug.
treecompose: Add ability to automatically detect atomic host IP

When creating imagefactory images, we now detect if there is a "default"
KVM network and if so, we grab its IP and dynamically substitute it into
the KS file.  This prevents a difficult to debug error for users who
use a different IP/subnet scheme on their KVM networks.

If we cannot detect the network and IP, we suggest the user static define
it in the KS file.

packaging/rpm-ostree-toolbox.spec.in: Added libvirt-python as a runtime
dependancy.
Upon trigger, run a treecompose.

We fork(), start a log file, run git-pull, then treecompose.
We log (to systemd) the start and completion.

This is kind of big, and in many ways ugly: it hardcodes a lot
of knowledge (git, treecompose commands, path to log file). It's
not terribly flexible. But that hardcoding has to happen somewhere,
and the alternative is to duplicate all that in multiple places
on the build server. This at least gives us consistency, helpful
log files, and a mechanism (journald) such that other processes
can trigger upon successful completion of a compose.
Scheduler: run only one compose at a time.

Testing in progress. Results look promising.
log_dir: avoid collisions.

If we ever start two composes within the same second, append
a sequence number (.1, .2, ...) to the output directory to
prevenctollisions.
git/HEAD can contain more than just branch name

...eg 'ref: refs/heads/mybranch'. Deal with it.