Add missing BlockMap params to init.
Have from_global_dim_dict call __init__.
Have from_axis_dim_dicts call __init__.
Refactor the alternate constructors not to use new.
WIP: Add from_maps classmethod (constructor).
Have from_dim_data_per_rank call from_maps.
Make __init__ into __new__ and have it call from_maps.
Have from_shape call from_maps.
Add and expand Distribution docstrings.
WIP: Rename __new__ to from_global_dim_data.
Update tests and usages.
Merge pull request #484 from enthought/refactor/client-map-constructors-use-init

Refactor client-side BlockMap constructors to call init
Merge pull request #485 from enthought/refactor/distribution-from-maps-constructor

Add a `from_maps` Distribution constructor
WIP: Rename from_shape to __new__.
Update tests and usage.
Make Map.slice return a Map...

Have Distribution.slice build a new Distribution out of these Maps.
Whitespace.
Merge pull request #486 from enthought/refactor/Distribution-default-constructor-is-from-shape

Make `from_shape` Distribution's default constructor
Merge branch 'master' into refactor/map-slice

Conflicts:
	distarray/dist/maps.py
Use distribution.targets instead of context.targets in decorators.py