- copy bbox on deserializzation (for memory alignment constraints)

- lwgeom_clone_deep / lwgeom_release_deep
  (or maybe should both be always be deep.... )

- LWGEOM editor (insert/append a geom, remove a geom, ....)
 
- Flatten(geometry) 

- F linemerge(linestring, linestring)

- A linemerge(linestring, linestring)

- Check spheroid misure functions
	o can't understand if 3d computation works since
	  I get same result w/ 2d and 3d.
	o check if distance can be computed in 3d space

- Check semantic required by OGC functions working on "first geometry
  of a given type". Is the first geometry be to be seeked inside 
  collection elements (currently it is not w/ LWGEOM) ?

- proj support functions might need 3d sometimes.