$ find * -type f |xargs perl contrib/scripts/spdx.pl
  $ git rm contrib/scripts/spdx.pl

We no longer add these. If you use Emacs, configure it yourself.

Also, due to our "smart-tab" usage the editor anyway does a subpar
job handling our tabs. However, on the upside every user can choose
whatever tab-width he/she prefers. If "smart-tabs" are used properly
(like we do), every tab-width will work.

No manual changes, just ran commands:

    F=($(git grep -l -e '-\*-'))
    sed '1 { /\/\* *-\*-  *[mM]ode.*\*\/$/d }'     -i "${F[@]}"
    sed '1,4 { /^\(#\|--\|dnl\) *-\*- [mM]ode/d }' -i "${F[@]}"

Check remaining lines with:

    git grep -e '-\*-'

The ultimate purpose of this is to cleanup our files and eventually use
SPDX license identifiers. For that, first get rid of the boilerplate lines.

- don't include "nm-default.h" in header files. Every source file must
  include as first header "nm-default.h", thus our headers get the
  default include already implicitly.

- we don't support compiling NetworkManager itself with a C++ compiler. Remove
  G_BEGIN_DECLS/G_END_DECLS from internal headers. We do however support
  users of libnm to use C++, thus they stay in public headers.

(cherry picked from commit f19aff89095ca192b8b2e37534b7a899aecd82f9)

In case, "$PREFIX/var/lib" does not exist, we want to create those
directories with permissions 755, not 700.

Rather than randomly including one or more of <glib.h>,
<glib-object.h>, and <gio/gio.h> everywhere (and forgetting to include
"nm-glib-compat.h" most of the time), rename nm-glib-compat.h to
nm-glib.h, include <gio/gio.h> from there, and then change all .c
files in NM to include "nm-glib.h" rather than including the glib
headers directly.

(Public headers files still have to include the real glib headers,
since nm-glib.h isn't installed...)

Also, remove glib includes from header files that are already
including a base object header file (which must itself already include
the glib headers).

Also react on SIGUSR1 and SIGUSR2, beside SIGHUP.
Only for SIGHUP actually reload the configuration from
disc. For the other signals only emit a config-changed
signal.

With this change, `NetworkManager --help` and `NetworkManager --version`
work for non-root user.

And rename the function to nm_main_utils_ensure_not_running_pidfile()
to match the other _ensure_ functions that exit(1).

Also no longer pass @name to nm_main_utils_ensure_not_running_pidfile()
and use g_get_prgname() instead.
nm_main_utils_ensure_not_running_pidfile() checks that the running
process has the same program name, so this changes behavior if the
user renamed the binary. Before, we would check whether the running
process is named 'NetworkManager' ('nm-iface-helper'). Now we check
whether the process has the same name as the current process.
This means, that if you rename the binary to 'NetworkManager2' we
would now only detect a conflicting 'NetworkManager2'. Before we would
only detect conflicting 'NetworkManager' binaries.

Also, don't use nm_log_err() as nm-logging is not yet setup.