signal for (De)ActivateConnection?

[mh mike franken de (Michael Hirmke)]

Hi *,

after one of the latest NetworkManager upgrades one of my perl scripts
stopped working, obviously because listening to dbus' NetworkManager
DeviceAdded/DeviceRemoved signals no longer covers my strongswan vpn
connections.
Using
  dbus-monitor --system "interface='org.freedesktop.NetworkManager'"
I see, that a PropertiesChanged signal is fired and a new entry
appears in the list of active connections, as soon as the vpn connection
is established.

So my question is: How do I handle this programmatically?
Do I listen to PropertiesChanged signals in addition to
DeviceAdded/DeviceRemoved signals? And if so, how do I know that
PropertiesChanged means that a new connection appeared and what
connection that is?

Version is NetworkManager-1.8.4-2.2.x86_64.

Thx a lot.

Bye.
Michael.
-- 
Michael Hirmke