Add __copy__ method to backend normaliz of Polyhedron

[kliem]

Currently, when copying a normaliz polyhedron, the _normaliz_cone is not copied appropriately:

sage: p = polytopes.hypercube(7,backend='normaliz')
sage: pcopy = copy(p)
sage: p == pcopy
True
sage: p is pcopy
False
sage: pcone = p._normaliz_cone
sage: pcopycone = pcopy._normaliz_cone
sage: pcone == pcopycone
True
sage: pcone is pcopycone
True

This ticket implements the __copy__ method in the normaliz backend by making use of the method NmzConeCopy of PyNormaliz. This way, a copy of a polyhedron with backend Normaliz contains a true copy of the normaliz cone.

CC: @jplab

Component: geometry

Keywords: polyhedra, normaliz

Author: Jonathan Kliem

Branch: d30c087

Reviewer: Jean-Philippe Labbé, Travis Scrimshaw

Issue created by migration from https://trac.sagemath.org/ticket/28633

[kliem]

Commit: ed7bfd2

[kliem]

Branch: public/28633

[kliem]

New commits:

ed7bfd2

polyhedra with backend normaliz make a copy of the cone when copying

[jplab]

comment:5

Optional flags are missing.

[sagetrac-git]

Changed commit from ed7bfd2 to d30c087

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

d30c087

added `# optional -pynormaliz`

[tscrim]

comment:8

LGTM. JP, I added you as a reviewer for comment:5.

[tscrim]

Reviewer: Jean-Philippe Labbé, Travis Scrimshaw

[vbraun]

Changed branch from public/28633 to d30c087

[jplab]

comment:10

Replying to @tscrim:

LGTM. JP, I added you as a reviewer for comment:5.

LGTM too.

[jplab]

Changed commit from d30c087 to none