Fix error message in _make_dimdata.
Add a failing test for specifying a dist of 'bc'.
Fix an `Examples` section for `init_map_classes`.

We don't have a `fast_maps` anymore.
PEP8 whitespace tweak.
Don't use mutable objects as default parameters

in construct.py.
Add a docstring and PEP8.
Fix line lengths.
Replace an explicit cast with true division.
Rename MapRegistry to MapCodeRegistry.

It's more descriptive.
Whitespace and line wrapping.
Re-linewrap some imports.
Move distarray/mpi/mpibase to distarray/mpiutils.

Also merge distarray/mpi/error into distarray/error and remove the mpi
subdir.  Flat is better than nested.  There wasn't enough in this subdir
to require a sub-package.
Move proxy.py into benchmarks.

It only contains a single plotting function.
Move the benchmark function into benchmarks.

Also fix the benchmark scripts.
Rename `core` subpackage to `local`.
Move random into local.  It was only one file.
Merge branch 'odin' into feature/simplify-architecture