Add support for OSM Scout Server routing V2

[rinigus]

With addition of Valhalla, OSM Scout Server supports new version of routing protocol - V2. This protocol follows Valhalla's API. Main changes when compared to V1:

• Routing points (target origin and points in between) have to be given as coordinates. So, client is supposed to apply geocoder itself before calling router. Use OSM Scout Server in this case to keep all operations offline.

• Routing response would be either Valhalla's response according to its API or libosmscout response in accordance with V1. Since V1 is implemented already, it should be easy to get that parsed.

• When user selected libosmscout as a routing provider in the server, the server will only use routing points to calculate the route and would determine the type of transpotration from provided JSON. All other Valhalla's API options are ignored.

• Valhalla's response encodes the route. See https://github.com/valhalla/valhalla-docs/blob/master/decoding.md for example code for decoding

There is an implementation in Poor Maps already. If licenses match, it should be easy to reuse that code.

[rinigus]

@M4rtinK : I wonder whether you had a chance to look into it? Or should I try to make the corresponding code?