Add viewbox parameter to Nominatim

[raphink]

Nominatim supports a viewbox parameter, which gives a higher priority to results in the current view. This is useful to find end points close to start points.

Unfortunately, this feature seems broken in Nominatim currently, but it will be useful once it's fixed.

[DennisSchiefer]

I'll add the viewbox parameter to the next release for the time being. In case it turns out that Nominatim will produce unintuitive results once it is fully implemented on their side, I will remove it again.

[DennisSchiefer]

I'll add the viewbox parameter to the next release for the time being. In case it turns out that Nominatim will produce unintuitive results once it is fully implemented on their side, I will remove it again.

[DennisSchiefer]

I'll add the viewbox parameter to the next release for the time being. In case it turns out that Nominatim will produce unintuitive results once it is fully implemented on their side, I will remove it again.