Migrate geocoder to new /v2/geocoder API call

[mvl22]

The geocoder needs to be migrated to the CycleStreets API V2:
https://www.cyclestreets.net/api/v2/geocoder/

at
https://github.com/cyclestreets/mobileweb/blob/master/js/cyclestreets.js#L912

[mvl22]

This is now available.

http://www.cyclestreets.net/api/v2/geocoder/

This brings the key benefit that you can return the full geometries, using geometries=1, so the map can be zoomed in, rather than merely be panned but stay at the same zoom level.