MeshTopology uses too much memory when initialising D-1

[Chris Richardson]

MeshTopology uses a lot of memory, especially in 3D, because it generates the connectivity D--D via D--0--D, when mesh.init(D-1) is called.

Probably this can be removed by using a different method, similar to that used in GraphBuilder.cpp

Perhaps connectivities between the same dimension should only be created when explicitly asked for?

[Prof Garth Wells]

Improvements made in 8265008.

See also http://fenicsproject.org/pipermail/fenics/2014-January/000954.html

[Prof Garth Wells]

Removing milestone: 1.4 (automated comment)