GNU R lightweight well-known geometry parsing

 Provides a minimal R and C++ API for parsing
 well-known binary and well-known text representation of
 geometries to and from R-native formats.
 Well-known binary is compact
 and fast to parse; well-known text is human-readable
 and is useful for writing tests. These formats are only
 useful in R if the information they contain can be
 accessed in R, for which high-performance functions
 are provided here.