Edit and simplify 'geojson', 'Spatial', and 'sf' objects. This is wrapper around the 'mapshaper' 'JavaScript' library by Matthew Bloch <https://github.com/mbloch/mapshaper/> to perform topologically-aware polygon simplification, as well as other operations such as clipping, erasing, dissolving, and converting 'multi-part' to 'single-part' geometries. It relies on the 'geojsonio' package for working with 'geojson' objects, the 'sf' package for working with 'sf' objects, and the 'sp' and 'rgdal' packages for working with 'Spatial' objects.