Radically simplify distarray.

1) Remove all the C-level MPI stuff
2) Remove all the Cython
3) Remove all the stuff needed to build the above
4) Restore the python `maps.py`
Rename `test_odin` so it won't be run by nose.

This solves our nosetest problem partially--all the other tests can be run with nose without a problem.  Those that require `mpiexec` will be skipped.  This allows us to remove the hacky `run_tests.sh` script as well.
Fix up the Makefile.
Move directories and files around.

1) Move `docs/examples` -> `examples`.
2) Move `docs/benchmarks` -> `benchmarks`.
3) Move `np_vs_distarray_timing.py` into `benchmarks`.
Simplify the INSTALL doc.
Slight formatting tweaks to README.
Add a test target to Makefile.
Fix typos in maps.py.
Whitespace tweaks.
Make division explicitly integer division.

For Py3 compatibility.
Whitespace.
Ensure all elements of grid_shape are ints.
Reduce test size for speed.
Whitespace.
Isolate an ndenumerate test.

This is taken from part of a test_distarray test.
Merge pull request #53 from enthought/feature/simplify

Simplify the codebase by removing C and Cython code (for now)