WIP: Redo maps, with new global-local separation.
Fix global_limits.
Fix TestLocalInd tests.
WIP: Remove references to LocalMap owner method.
WIP: Generalize maps

Add docstrings to maps, fix tests for maps.py.
WIP: Fix map creation in `base`.

Add a couple of simple, non-parallel test cases for `BaseLocalArray`.
WIP: Remove a couple of no-longer-used functions

... from `construct`.
Reorder some imports in denselocalarray.
WIP: Fix creation of `LocalArray`s with `__init__`.

This fix allows incomplete `dimdata` data structures to be passed to `BaseLocalArray.__init__`, which will then be filled out if possible.
Move and remove some functions and do cleanup.
Fix tests and bugs in `paralleltest_localarray`.
Fix tests for `random`.
Fix some of the distarray protocol tests.
Unskip and fix DAP tests.
Remove owner_ related calls from client.
Fix a Python 3 incompatibility.
Fix an error in how 'gridrank' keys are set.

The error was that 'rank' was being used instead of the proper index of 'cart_rank' for each dimension.
Fix __getitem__ and __setitem__ in client.

Warning: a a bit hacky.
Fix some python 3 incompatibilities.

`x.next() -> six.next(x)`
and `mydict.items() -> list(mydict.items())`
Remove an unused import.