Remove leftover C and Cython files.
Improve the `test` target in the Makefile.
Clean up the test calls in the Travis-CI yaml file.
Clean up `distarray/core/error/`.

One exception class (out of many) doesn't have the word "Error" at the end.  I fix this.  Also, for some reason it's reimplemented in the only module it's used in.
Capitalize error messages.
Remove `*` imports, except in `__init__.py`s.

Replace with explicit `from` imports.
Whitespace.
Remove unused imports.

Identified by `pyflakes`.
Add a docstring to `run_ipcluster`.
Remove unused variables.

Identified by `pyflakes`.
Fix `LocalArray.copy(...)`.

It didn't actually return anything before.
Fix some mistaken / missing references.

1) `numpy` doesn't have `binary_or` or `binary_xor`; replace these with `bitwise_or` and `bitwise_xor`.

2) the `mod` function was referenced, but missing, so add it.
Fix a typo that probably broke this test.
Capitalize error messages in `denselocalarray`.
Be more explicit about `sync` not being implemented.
Capitalize error messages.
Small PEP8 whitespace change.
Rearrange imports.
Add a simple "does it run test" for unary ops.
Rename a test (a missed rename from the Great Rename).