MeshEntityIterator over empty Mesh

[Chris Richardson]

Sometimes, especially in parallel, an empty Mesh may occur. Ideally, it should be possible to iterate over these empty meshes without crashing.

For a really simple python example:

mesh = Mesh()
for v in vertices(mesh):
    print v.index()

[Anders Logg (Chalmers)]

Removing milestone: 1.7 (automated comment)

[Prof Garth Wells]

Let's fix this in 2018.1 with the pybind11 change, which does affect the iterators.