NMDeviceWired: don't unconditionally access device.active_connection

The active_connection might be null, but the NMApplet code might
still belive the device wrapper is the primary connection (because
dbus signals are emitted one after the other).
(Also, remove an old and wrong comment about bluetooth in wwan code)

Fixes:

(gnome-shell:22511): Gjs-WARNING **: JS ERROR: Exception in callback for signal: icon-changed: TypeError: this._device.active_connection is null
NMDeviceWired<.getIndicatorIcon@resource:///org/gnome/shell/ui/status/network.js:475
wrapper@resource:///org/gnome/gjs/modules/lang.js:169
NMApplet<._updateIcon@resource:///org/gnome/shell/ui/status/network.js:1790
wrapper@resource:///org/gnome/gjs/modules/lang.js:169
_emit@resource:///org/gnome/gjs/modules/signals.js:124
NMConnectionSection<._addConnection/<@resource:///org/gnome/shell/ui/status/network.js:265
_emit@resource:///org/gnome/gjs/modules/signals.js:124
NMConnectionItem<._sync@resource:///org/gnome/shell/ui/status/network.js:137
wrapper@resource:///org/gnome/gjs/modules/lang.js:169
NMConnectionItem<.setActiveConnection@resource:///org/gnome/shell/ui/status/network.js:169
wrapper@resource:///org/gnome/gjs/modules/lang.js:169
NMConnectionDevice<._activeConnectionChanged@resource:///org/gnome/shell/ui/status/network.js:327
wrapper@resource:///org/gnome/gjs/modules/lang.js:169

https://bugzilla.gnome.org/show_bug.cgi?id=723570
NetworkMenu: update for latest designs

Distinguish reaching the full internet from being in a non-routed
LAN, and show a different icon when being an hotspot master.

https://bugzilla.gnome.org/show_bug.cgi?id=723570
NetworkMenu: fix connection name update

If the connection name is changed, the UUID doesn't necessarily,
so checkConnection would take the early return path. Make sure
we update the existing menu item too.

https://bugzilla.gnome.org/show_bug.cgi?id=723570
NetworkMenu: sort connections by name only

We don't watch for timestamp changes, and sorting by name keeps
the order consistent and predictable. In practice, there should
be at most 3 or 4 elements, so the user will always read all them
at once and sorting is irrelevant.

https://bugzilla.gnome.org/show_bug.cgi?id=723570
NetworkMenu: use radio items instead of switches for multiple profiles

Multiple connections for the same device are mutually exclusive, so
a switch is not the appropriate UI metaphor. Use a radio item instead,
and provide a separate "Turn off" item to disconnect.
Behavior when there is only one connection is not changed, there
is a single Connect/Turn off item.

https://bugzilla.gnome.org/show_bug.cgi?id=723570
ShellApp: remove impossible check

The action muxer is created and destroyed with the running state,
it can never be NULL.

https://bugzilla.gnome.org/show_bug.cgi?id=722554