#943 - Update convexhull

[mforets]

Closes #943.

[schillic]

I would wait for the answer in Polyhedra. If this is removal is performed internally, there is no need to do it again on our end.

[mforets]

It is intended that removevredundnacy! is used outside convexhull, so i suggest to use this branch after we figure what was is making it to fail.

[mforets]

Ok, found the error: the problem explained in the commented part seems to be fixed now:

        # Note: The redundant vertex v5 is not removed (see #561).
        # This test can be removed (and the length above should be corrected)
        # when that issue is resolved.
        @test length(vl) == 5 && v5 ∈ vl

[schillic]

Okay, this will not be fixed upstream, so we have to do it on our end.

[schillic]

I added above that this PR closes #561, but now I see that there is a second issue there.

the constructor of VPolytope does not remove redundant vertices.

I will hence add an optional argument removeredundancy::Bool=true to the default constructor.

EDIT: On second thought, there is more to do, so to keep this PR small, we can do that in another PR.