lwnurbscurve_construct

[Paul Ramsey]

Loic,

In lwnurbscurve_construct the weights and knots are deep copied, but
the ptarray is passed in and ownership taking in the lwgeom, why so?
Why not just passively take ownership of all the input arrays?

https://github.com/postgis/postgis/blob/master/liblwgeom/lwgeom_nurbs.c#L139

Also wondering why the source file is not lwnurbscurve.c to match up
with the other type-specific files (lwline.c, lwpoint.c, lwpoly.c)
that contain constructors and the like.

P.