Show text information as map overlay

[ocroquette]

Currently the textual information is displayed as independent div on top of the map. This wastes a lot of screen real estate, especially on tablets and PCs.

Display it instead as map overlay, for instance with L.control.

The route length could be displayed also in the progress bar, as in the Android app.

Also, the route name and length should always been displayed, not only during the event.