wkb 0.4-0

Change to which WKB representations SpatialPolygons convert to
- SpatialPolygons objects now convert to either WKB Polygons or WKB MultiPolygons
  - If each Polygons object in the SpatialPolygons object contains a single Polygon object with only one exterior boundary then convert to WKB Polygon, otherwise convert to WKB MultiPolygon
  - Previously SpatialPolygons were converted to WKB Polygon containing multiple rings
Make changes for compatibility with R 4.0.0 (#12)

wkb 0.3-0

Improved performance of function hex2raw() (#10)

wkb 0.2-0

Added support for big-endian WKB (#2)
Added function hex2raw() (#4)
Added tests

wkb 0.1-0

First CRAN release