This adds a global "--offline" option and allows its use with "add" and
"modify" commands. The "add" looks like this:

  $ nmcli --offline conn add type ethernet ens3 ipv4.dns 192.168.1.1 \
      >output.nmconnection

The "modify" is essentially implementing what's been suggested by
Beniamino in bugzilla ticked (referred to below):

  $ nmcli --offline connection modify ens3 ipv4.dns 192.168.1.1 \
      <input.nmconnection >output.nmconnection

Other commands don't support the argument at the moment:

  $ nmcli --offline c up ens3
  Error: 'up' command doesn't support --offline mode.

https://bugzilla.redhat.com/show_bug.cgi?id=1361145

Make the order of nmc_complete_strings() arguments consistent with the
multi-way conditional below. Doesn't have any effect, just ensures the
ommisions and mistakes are hopefully easier to spot.

Follow-up commits are going color Wi-Fi networks and connections that rely
on deprecated features differently, to provide a visual cue.

Add color definitions for those.

This is vestigal. It has been in place, because we'd be turning off echo
ourselves when asking for password and needed to make sure we'd still
terminal in original state upon unexpected termination.

This shouldn't be necessary since commit 9d95e1f1753a ('clients/cli: use a
nicer password prompt') we let readline take care of this and also clean
up after itself in nmc_cleanup_readline().

https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/merge_requests/1100

We use clang-format for automatic formatting of our source files.
Since clang-format is actively maintained software, the actual
formatting depends on the used version of clang-format. That is
unfortunate and painful, but really unavoidable unless clang-format
would be strictly bug-compatible.

So the version that we must use is from the current Fedora release, which
is also tested by our gitlab-ci. Previously, we were using Fedora 34 with
clang-tools-extra-12.0.1-1.fc34.x86_64.

As Fedora 35 comes along, we need to update our formatting as Fedora 35
comes with version "13.0.0~rc1-1.fc35".
An alternative would be to freeze on version 12, but that has different
problems (like, it's cumbersome to rebuild clang 12 on Fedora 35 and it
would be cumbersome for our developers which are on Fedora 35 to use a
clang that they cannot easily install).

The (differently painful) solution is to reformat from time to time, as we
switch to a new Fedora (and thus clang) version.
Usually we would expect that such a reformatting brings minor changes.
But this time, the changes are huge. That is mentioned in the release
notes [1] as

  Makes PointerAligment: Right working with AlignConsecutiveDeclarations. (Fixes https://llvm.org/PR27353)

[1] https://releases.llvm.org/13.0.0/tools/clang/docs/ReleaseNotes.html#clang-format

The libreadline starting from version 6 is licensed as GPLv3. For some
use cases it is not acceptable to use this license.

In the NetworkManager the libreadline is used by nmcli.
This change allows using libedit instead of libreadline.

Following adjustments were made:
1. The history_set_history_state() is not supported in the libedit.
   Instead, the where_history() with remove_history() were used to remove
   the history content if needed.

2. rl_complete_with_tilde_expansion - it is the binary flag used only
   when one wants to have the expansion support. The libedit is not
   supporting and hence exporting this flag.

Subjectively, I think this looks better.

We get it now always by "nm-macros-internal.h".