Maintain the topology of polygons (to allow nice zooming)

[mayeulk]

When zooming at https://github.com/unhcr/dataviz/blob/master/js/worldtopo.json one can see that the topology is not maintained.

Ways to simplify polygons while maintaining the topology are discussed here:
https://gis.stackexchange.com/questions/185040/simplify-geometries-but-keep-them-contiguous
https://gis.stackexchange.com/questions/178/simplifying-adjacent-polygons/
https://trac.osgeo.org/postgis/wiki/UsersWikiSimplifyPreserveTopology
https://trac.osgeo.org/postgis/wiki/UsersWikiSimplifyWithTopologyExt

This is in view of another possible improvement, namely to render zooming possible (in a visually appealing way)

[mayeulk]

These are possibly other useful links/discussions:
https://github.com/topojson/topojson-simplify
Filter and simplify geometries while preserving topology for smaller files and faster rendering

topojson/topojson#275