[CGAL] Fix build problem

[bcarrez]

CGAL plugin has some build issues in some circumstances, this PR aims to fix it:

• build error if "image" plugin is deactivated
• BOOST_PARAMETER_MAX_ARITY too low by default (5 by default, where CGAL needs 12 at least)

---

This PR:

• builds with SUCCESS for all platforms on the CI.
• does not generate new warnings.
• does not generate new unit test failures.
• does not generate new scene test failures.
• does not break API compatibility.
• is more than 1 week old (or has fast-merge label).

Reviewers will merge only if all these checks are true.

[bcarrez]

There is still a build problem with the "image" plugin. See issue #352 .

[guparan]

[ci-build]

[guparan]

Hi @bcarrez, is this PR still wip?

[bcarrez]

This PR is not WIP anymore and is ready to review.