support for hexEwkb

[rduivenvoorde]

support for extended wkb like postgis

you can obtain many hexewkb representations with postgis:

=> SELECT 'POINT(0 0)'::geometry; -- will give you hexewkb for that

Note that hexEwkb is hex of the extended wkb, which is an extension
of PostGIS to possibly include SRID and higher dimensions (z,m).
The above (a point with no SRID and 2d) would be equivalent to the
official WKB, but this would be extensions:

=> SELECT 'SRID=4326;POINT(0 0)'::geometry;
=> SELECT 'POINT(1 2 3)'::geometry;
=> SELECT 'POINT(1 2 3 4)'::geometry;
=> SELECT 'POINT M (1 2 4)'::geometry;