Ported using KDELibs4Support, for a smaller delta, so we can keep
developing on master until we decide not to.
At the moment, it builds and installs but tests don't pass because
of a QCA2 initialization problem I didn't manage to debug yet.
CCMAIL: kdeconnect@kde.org
Due to bug occured in QML property access(when object derived from QDBusAbstract interface) C++
part of BatteryPlugin in plasmoid rewritten in pure QML.
BatteryPluginDBusInterface fixed to avoid this bug.
Bug occuring when QML try to access any property of any object derived from
QDBusAvstractInterface - QML engine crashes.