Better icon for notifications, avoid foreground service
Summary:
Remove foreground service permission
Stop using singleton for MQTTClient, since each is bound to a service
Reviewers: valerio.bozzolan
Reviewed By: valerio.bozzolan
Subscribers: valerio.bozzolan, Libre BusTO
Tags: Libre BusTO
Differential Revision: https://gitpull.it/D156