Move BaseLocalArray into localarray.py.
Move utility functions from base to localarray.
Remove base.py.
Rearrange imports.
Move arecompatible function (within file).
Merge BaseLocalArray into LocalArray.
Rearrange imports.
Rearrange imports.
Add global context at distarray.world.WORLD
Test distarray.world.WORLD exists.
Tests should not "clear" engines.
Merge pull request #208 from cowlicks/global-context

Global context
Merge branch 'master' into feature/remove-baselocalarray
Merge branch 'master' into feature/generalize-cart-comm

Conflicts:
	distarray/local/base.py
	distarray/local/localarray.py
	distarray/local/tests/test_base.py