Tweak docstrings and blank lines.
Group distribution-related keys in API.
Make load_npy take a Distribution
Make load_hdf5 take a distribution
WIP: Change {empty,zeros,ones} to take distributions

instead of shape/dist/grid_shape
WIP: Change fromndarray to take a distribution object.
Fix a usage of `empty` in decorators.
Fix tests.
Fix examples.
Add simple docstrings.
Add better docstrings.
Modify client-side random functions to take a distribution.

Also, fix the tests.

All of these functions have been modified to take a distribution as a required argument, whereas before, some of them could be called without shape/dist/grid_shape parameters to return a single scalar.  This didn't seem to be an important use-case (one could just use the appropriate numpy function for that), so I omitted it.
Merge branch 'master' into feature/random-array-creation-takes-distribution

Conflicts:
	distarray/dist/decorators.py
	distarray/dist/tests/test_context.py
	distarray/dist/tests/test_decorators.py
	distarray/dist/tests/test_distributed_io.py
	distarray/dist/tests/test_random.py
Fix import in plotting.py
Fix plotting examples
Merge branch 'bugfix/fix-plotting-after-refactor' into bugfix/refactor-broke-docs

Conflicts:
	examples/plot_distarray_block_axis_0.py
	examples/plot_distarray_block_axis_1.py
	examples/plot_distarray_block_block.py
	examples/plot_distarray_block_cyclic.py
	examples/plot_distarray_cyclic_cyclic.py
Fix API docs and docstrings.
Move uid and DISTARRAY_BASE_NAME to utils.
Add `apply` function which is analogous to IPython.parallel's apply.
Tests for new apply function.