vztmpl-dl: add --upload-all, --ignore-errors

Before this patch, there was no easy way to update all existing
OS templates. Theoretically, it could be done using something like

	vztmpl-dl $(vztmpl-dl --list-local)

Practically, such command would exit on the first template which can't
be found remotely (such as, say, old fedora which moved into
unsupported).

So, --ignore-errors option is added to keep downloading templates, even
if some of those were not found.

Next, instead of invoking vztmpl-dl two times, let's just add
--update-all option, which is an equivalent of

	vztmpl-dl --ignore-errors --update $(vztmpl-dl --list-local)

Finally, document new options in --help output and the man page.

Signed-off-by: Kir Kolyshkin <kir@openvz.org>
2 files changed