mapBubble: Fix margins
mapView: Do not show turnPoint marker for stops

https://bugzilla.gnome.org/show_bug.cgi?id=737318
turnPointBubble: Do not include instruction

It feels redundant to have the instruction in the bubble
as well as on the line you just clicked.

https://bugzilla.gnome.org/show_bug.cgi?id=737318
Animate going to turnPoint

Set a linear transition and a fixed zoom for going to a
turning point.

https://bugzilla.gnome.org/show_bug.cgi?id=737318