Fedora 32 drops "python" from the path. Hence "/usr/bin/env python" won't
work anymore. Of course, who needs a way to invoke the interpreter that works
accross different distributions! WTF.

In this case, easy to work around. We run it from meson, so we have access to the Python 3
binary. Just call it directly like we do for autotools.

NM_DEVICE_MANAGED was intended to work like NM_DEVICE_AUTOCONNECT:
namely it would call the D-Bus property setter synchronously.

But such behavior is horrendous, we certainly don't want blocking calls
during a property getter.

Luckily this one instance was unused and never worked as the property
was marked as G_PARAM_READABLE. Just drop the setter.

Synchrnous initialization is problmatic and needs cleanup.

get_permissions_sync() is an internal function, that has only one
caller. We need to keep track of functions that make synchronous D-Bus
calls. Move the synchronous call into the caller, so that it's clearer
who calls such API.

Currently, we don't use private sockets. We are always connected
to D-Bus.

We don't need a wrapper around g_bus_get*(). Just use
it directly.

I guess in the past this had some use when we were using
a private socket too. Those days are gone. If we are going
to re-introduce private socket support, then we probably should
come up with a better solution.

Introduce libnm API to reload NM configuration through the Reload()
D-Bus method.

Flags to the manager Reload() method are stable API but not exposed in
a public header. Export them.

https://gitlab.freedesktop.org/NetworkManager/NetworkManager/merge_requests/270

This will make NetworkManager look up APN, username, and password in the
Mobile Broadband Provider database.

It is mutually exclusive with the apn, username and password properties.
If that is the case, the connection will be normalized to
auto-config=false. This makes it convenient for the user to turn off the
automatism by just setting the apn.

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