feature request: stop automatically when unplugged or disconnected from wifi

[slush0]

Thanks a lot for ABCore, its simply amazing it is possible to run Core on Android devices!

There's one small feature missing which allow me to use ABCore on its full potential on my devices. Please implement inverted feature of #32; it would be nice to automatically stop ABCore when the device is disconnected from power supply OR if it disconnect from Wifi (for example to metered mobile data).

This would prevent to discharge my phone or wipe my data plan. Actually, both happened to me already :-). I believe that because #32 is already implemented, implement the opposite will be quite straightforward.