Make synopses more concise in various place, improve
consistency of formatting, and fix some small mistakes
and oversights.
Closes: #2307
Approved by: matthiasclasen
Copying refs from the system repo into a repo on a USB drive requires
the summary in the system repo to be up to date (and similarly for other
flatpak installations like a per-user one). At the moment we expect the
user to run `sudo ostree summary -u` before `flatpak create-usb` which
is a bad user experience. Another option is to set
`core.auto-update-summary` to true on the ostree repo config, but there
are significant performance concerns with that: it involves updating the
summary after every transaction rather than only when we need it. So
this commit changes the create-usb command to use the "UpdateSummary"
system-helper method to update the summary in the source repo before
copying to the destination. This strategy allows us to continue to let
non-root users use `flatpak create-usb`. This commit also tries to
update the remote repo metadata and appstream data for each remote
before copying to the USB, because we can now do that without
invalidating the summary.
Closes: #1945
Approved by: alexlarsson
Since the create-usb command doesn't run as root (and if it did GNOME
Software wouldn't be able to call out to it), it can't update the
summary file in the source repo if the system installation is being
used. So the user is expected to run `ostree summary -u` before using
create-usb. But if the create-usb command then updates the appstream
data and repo metadata refs, the summary will no longer point to the
latest commits on those refs. As a short term fix, avoid updating the
appstream data and repo metadata, and mention in the manpage that the
user should do so. The better solution, not requiring any manual steps
on the user's part, will require a fix for
https://github.com/ostreedev/ostree/issues/1664.
