Show lines without any arrival times separately

Summary:
Show the lines for which no arrivals are found at the bottom, with only the line name in a bubble. This is useful especially in the night to avoid taking up unnecessary space on the screen.

On the technical side:

• Stop using listfragment as base for arrivals fragment
• Use recyclerview for the arrival times

Reviewers: valerio.bozzolan

Reviewed By: valerio.bozzolan

Subscribers: valerio.bozzolan, Libre BusTO

Tags: Libre BusTO

Differential Revision: https://gitpull.it/D119