This enables the handlers to be used for hosts which use a non-standard
port, such as is offered by some commercial services. Default to port
22, so it's optional and backwards-compatible.

This fixes cases where the day component of the when parameter resolved
to a non-zero padded integer under 10, such as "when = 1st at 01"

The comparison against the nowday variable failed consistently since
the date command format used always returned a zero-padded two digit
integer.

The solution chosen is to avoid generating nowday with zero-padding and
remove any zero-padding from whenday parameter using a more thorough
sed pattern which now also removes any non-alphanumeric characters from
the string.

The capital-V is more common as shorthand for --version, since many
commandline tools use -v as a shorthand for --verbose.

New option "--version"

See merge request riseuplabs/backupninja!18

At build time, we use the version number provided by configure.ac, which
is updated upstream when there is a new release.

This should help with testing development code and new releases. To use,
just install vagrant and run vagrant up && vagrant ssh

The former is deprecated, and automake complains

Fixes for configuration files without suffix.

Closes #11287

See merge request riseuplabs/backupninja!16

Error out if cache directory does not exist when creating a fresh dup backup

See merge request riseuplabs/backupninja!15

Support LUKS in disk partitions

See merge request riseuplabs/backupninja!13

Exclude zram devices, they don't have a partition table

See merge request riseuplabs/backupninja!12

Attempt to sanitize the database identifiers, fix #11285

Closes #11285

See merge request riseuplabs/backupninja!11

Borg support (rebased)

See merge request riseuplabs/backupninja!10

This adds the ability to specify an alternative SSH port within
the host variable.

Removing the quote and semicolon characters should be sufficient to
prevent breaking out of the shell command, but this may need reviewed
by someone more knowlegeable in shell scripting.

This allows the handler to fully make use of the advanced command-line
options for "borg create", such as the replaced "exclude*" options and
others like "--read-special" and "--numeric-owner".

Otherwise the handler may hang, waiting for user input. This may occur
when the borg cache is deleted, or when borg is upgraded.

The effect of "keep*" options is not straightforward to understand, so
replacing it with a simpler "keep" option, which replicates the
functionality of other backupninja handlers. This also simplifies the
helper, as the use is then only asked how many days of backups to keep.

At the same time, we add "prune_options" which allows for the use of the
"keep*" options as well as other useful prune options, like "--prefix".

In some cases it may be desirable to skip repository initialization, for
example when the repository is located at the root of a mount point.