Add map fragment and fix stuff


Add map fragment and fix stuff

Fix location following in the map

Use AsyncTask to load data

Fix map stuff and add comments

Fix database connection leak

Fix warning of unchecked operations

Test Plan: Check it builds and it doesn't crash

Reviewers: valerio.bozzolan

Reviewed By: valerio.bozzolan

Subscribers: valerio.bozzolan, Libre BusTO

Tags: Libre BusTO

Maniphest Tasks: T427, T1

Differential Revision: https://gitpull.it/D56