Adds cleanall makefile target.
Rename things in client_map.py

In the last rename, I saw nested sequences of dimension dictionaries being passed around and thought they were all `dim_data_per_rank` structures.  They are not; some of these are a de-duplicated zip of `dim_data_per_rank`.  Here give those things their own name (`axis_dim_dicts`) and add in some comments.

Also, rename `compactify_dicts` to `_dedup_dim_dicts`, which I think is a slightly better name and give `map_from_axis_dim_dicts` a leading underscore, since it shouldn't be part of the public interface.
Merge pull request #348 from enthought/feature/cleanall-target

Adds cleanall makefile target.
Merge pull request #350 from enthought/refactor/fix-client-map-names

Rename things in client_map.py
Put client side modules in distarray/client/ and change imports.
move client.py -> distarray.py and change imports to reflect this.
move DISTARRAY_BASE_NAME into top level __init__.py

This is because dacluster should not have to impor distarray/client/ to
clean things up.
Fix circular import issue with distarray.py
client_maps.py -> maps.py. add __future__.absolute_import where needed.

Since the module distarray/client/distarray.py's name conflicts with the
package name we import `absolute_import` everywhere in the file.
rename client directory to dist
Remove cruft from bad rebase.
Move utils to distarray/utils/.