Fix introduction, add new icon to detail map to stop location, bugfixes
Summary:
- Don't show permission button for location on Android 21
- Remove markers from the map when they are assigned a different direction
- Fix new button position
- Add icon to map in LinesDetailFragment to stop using GPS, fix bug in MQTT
Reviewers: valerio.bozzolan
Reviewed By: valerio.bozzolan
Subscribers: valerio.bozzolan, Libre BusTO
Tags: Libre BusTO
Differential Revision: https://gitpull.it/D148