Fix some memory leaks...

And:
* Renamed "Ariplane Mode" to "Offline Mode"
* Other cleanup.
Use compact class for ConnMan Service properties

This is better than pretending we have individual properties.
More work on wifi

* Added Scan WiFi button
* Cleaned up some names
* Fixed display of signal strength for wifi only
Add Connect/Disconnect button for network connections
Add ConnManAgent to request passwords and such.