Specifying 'none' is really not exclusive. We may want to say that the modem can
either authenticate with a given protocol, or otherwise just try without
authentication.
The reality is that 'none' itself is usually always given in the connection
settings.
For bearers using STATIC or DHCP IP method, the modem itself is the one
negotiating authentication with the network. The new `allowed-auth' property
allows users to specify which authentication method(s) are allowed to be used.
See the following NetworkManager commit for more reference:
commit 34aef8aaaa09b7473b9496aa49e550bd2def03f8
Author: Andrew Bird <ajb@spheresystems.co.uk>
Date: Thu Mar 15 16:19:43 2012 -0500
It's pointless to have libmm-common around, just merge it into libmm-glib and
make ModemManager depend on libmm-glib directly. At the end, the non-common
stuff in libmm-glib is really minimal.