[postgis-devel] GEOS centroid

[strk]

I've added a geoscentroid function to postgis.
To enable it:

CREATE FUNCTION geoscentroid(GEOMETRY)
        RETURNS GEOMETRY
        AS '$libdir/../libpostgis.so.0.8'
        LANGUAGE 'C' WITH (isstrict);

So far you explicitly decide which version to use (centroid or geoscentroid).
Let me know about further steps we should take ( automatic geos use when
available? )

--strk;