Switch logging to include filename + line numbers.
Implement table destruction.
Fix TileAccum

It was not returning the old tile; this resulted in None being
stored in the table in it's place.

Implement distarray.update()
Great renaming, part ...

spartan.pytable -> spartan.{wrap,api,__init__}

Move wrappers out of the __init__ file.
Logging now redirects to the C++ logger.
Support for zero-d arrays (aka scalars)

These are represented as extents with empty upper-left and size.

Add tests for sum(axis=None) which includes writing and reading from a zero-
d array.

Cleanup split computation a bit (itertools.product comes in handy).

Move tile accumulation logic to tile.py.

Move DistArray static methods to be module level functions instead.