The attached patch implements simplicial complexes, chain complexes, and their homology. Some examples:
```
sage: S = SimplicialComplex(1, [[0], [1]]) # a two-point space
sage: S2 = S*S*S …
Including pictures in the documentation is easy: a new "pictures" directory in doc/en/reference and a quick patch to MANIFEST.in to make sure the contents of that directory are included in distribut…