Display total query status somewhere

[matejdro]

After I restart openzwave-qt, it takes a while for the network to completely start up. Unfortunately, admin does not display current status of this discovery so I'm never sure when the network is ready. I'm currently just quickly selecting all devices and checking if all of them have Complete status, but it is pretty tedious procedure.

Counter like 5 / 21 mains devices queried in the status bar would be small, but helpful addition.