Unmanaged device still showin in nm-applet UI

[Robby Workman <robby rlworkman net>]

This was briefly mentioned on IRC to dcbw while working with another user
on a different (barely) related problem, and it spurred me to do some more
research.

The short-ish summary is that libvirt's virbr0 interface is not getting 
removed from e.g. nm-applet's list of connections. For the sake of clarity,
there's no real *problem* with this aside from inconsistency, as it no
longer shows up there when I define it as an unmanaged connection in
the [keyfile] section of NetworkManager.conf, and so it seems to me that
it should also be invisible there if it's marked as unmanaged by the 
system's udev rules.

First, the udev rule looks like this:
  [rworkman liberty ~]$ grep veth /lib/udev/rules.d/85-nm-unmanaged.rules 
  ENV{ID_NET_DRIVER}=="veth", ENV{NM_UNMANAGED}="1"

While running "udevmonitor -p" in another terminal to see the results,
I run "udevadm trigger --action=change --subsystem-match=net" and see
the following in the udevmonitor terminal:

  UDEV  [653.071290] change   /devices/virtual/net/virbr0 (net)
  ACTION=change
  DEVPATH=/devices/virtual/net/virbr0
  DEVTYPE=bridge
  ID_MM_CANDIDATE=1
  ID_NET_DRIVER=bridge
  IFINDEX=4
  INTERFACE=virbr0
  NM_UNMANAGED=1
  SEQNUM=4356
  SUBSYSTEM=net
  USEC_INITIALIZED=908332
  
  UDEV  [653.072176] change   /devices/virtual/net/virbr0-nic (net)
  ACTION=change
  DEVPATH=/devices/virtual/net/virbr0-nic
  ID_MM_CANDIDATE=1
  ID_NET_DRIVER=tun
  IFINDEX=5
  INTERFACE=virbr0-nic
  NM_UNMANAGED=1
  SEQNUM=4357
  SUBSYSTEM=net
  USEC_INITIALIZED=907541

So it appears to be set correctly as unmanaged. 

However, if I tell nm-applet to Disconnect it, it does so. My understanding
is that setting it as unmanaged would remove the possibility to do this, 
which is exactly what I want. I can of course work around this by setting it
as unmanaged in the NetworkManager.conf, and I'm not opposed to doing that,
but it seems that this is a bug. 

Is there a problem on my system or something in NM? I'm on NM-1.0.8 and
nm-applet-1.0.8 on Slackware -current (devel) with 4.3.0 kernel, if that's
relevant.

-RW