Fixes bug with cart_coords LocalArray property.

Includes regression test.
Rename `save` -> `save_dnpy` and similarly `load.`
assertEquals -> assertEqual

dude.
Merge pull request #223 from enthought/bugfix/fix-cart-coords-local-property

Fixes bug with cart_coords LocalArray property.
Merge branch 'master' into feature/rename-save-and-load
Change some docstring refs to `.dap` to `.dnpy`.
Improve the docstrings for save/load_dnpy.
Add '.noseids' to .gitignore
Merge pull request #224 from enthought/feature/rename-save-and-load

Rename `save` -> `save_dnpy` and similarly `load`
Added list() for python3.
Merge branch 'master' into feature/purge-command