Document "secret" functionality that allows to import new factory image.

Add support for updating factory image without need to provide exact
link.

I forgot to shift arguments after parsing -c option.

Karel Koci authored 3 years ago and Michal Hrusecky committed 3 years ago

Although JSON is a good format for parsing in languages such as Python
it gets too complex for shell parsing. The CSV format is way better for
that.

Turns out that we are actually using the parsed configuration in showing
help, so let's keep all the configuration together. It is nicer that way
anyway. But let's move the die function to the top so we can use it
during configuration parsing. Fortunately we don't need die_hepling
function which would cause a cycle.

It has some naming conflicts with functions we use and overwrites them,
so move it back to the beginning so it wouldn't break other stuff.

* In listing snapshots, the snapshot number does not necessary need to
  be a number anymore, especially with remote snapshots. So let's put ti
  in quotes so it is always a string.
* Error our when cleanup is called with invalid arguments.
* Error out early if we can't even create temp directory.
* Error out early if we can't guess the device to work on.
** Move configuration parsing to the end right before commands processing

Support multiple files with patterns excluded from backup.

We might want to add few extra files to the exported tarball. Like some
uci-defaults script to adapt configuration to new hardware - change the
MACs to the correct ones and if serial changed, regenerate device token
and such.

We might want to exclude various certificates during export, especially
fosquito ones that are tied to serial number and thus will not work on
other/replacement device.

Put quotes in correct places where davfs expects them, escape
potentially dangerous characters like spaces in passwords and make sure
the final secrets file have permissions required by davfs.

Extend syntax to allow smb:3.1.1://host/share URLs to specify specific
dialect of Samba to speak.

approximately halves the time schnapps list takes at the cost of being a
bit less generic

Drop mixed in tabs and update copyright.

Sometimes you have a lot space on your server and want to delete backups
manually.

Make sure sshfs mounting actually succeeded before continuing.

`generic_list` should not list only numbered snapshots, but also named
snapshots for example in remote case.

There was already a cleanup function before that does something
different, so renaming the trap cleanup to avoid overriding it.