This is for backward compatibility. We may want to add more testing
functions if other folks run into problems in the 1.10 release.

Also fix "*" imports.

The formatting of test arrays is not fixed for multiple spaces following
"," and other violations that are common in tests. To be precise, E241
and E201 are added to the errors that are excluded.

The np.rank was deprecated in 1.9.0.
Add test for deprecation.

Also

* Add __all__ to numpy/ma/testutils.py
* Remove various stray "#"

We might want to consider removing/refactoring both numpy/ma/bench.py
and numpy/ma/timer_comparison.

Most of these fixes involve putting blank lines around

.. versionadded:: x.x.x

and

.. deprecated:: x.x.x

Some of the examples were also fixed.

1.10 deprecated removal

This is to make it easier to find and remove deprecated features.
It would be a good idea if all deprecations were made with similar
comments.

Viewing an ndarray as a np.recarray now automatically converts
the dtype to np.record.

This commit also fixes assignment to MaskedArray's dtype attribute,
fixes the repr of recarrays with non-structured dtype, and removes
recarray.view so that viewing a recarray as a non-structured dtype
no longer converts to ndarray type.

Fixes #3581

For a masked array holding objects that themselves are arrays, when selecting a
single item, it is treated as if it were a slice of the array and an attempt is
made to set its mask.  This was always a bug, but it become visible with a
recent change to `MaskedArray.__getitem__` (gh-4586) where it is attempted to
change the shape of the mask.  With this PR, this case gets special  treatment
in that the object is made into a Masked Array with a full set mask.
(A previous attempt to do the perhaps more logical think and just return
`masked` caused quite a few errors in astropy.io.votable; it seemed it was
not worth breaking backwards compatibility that much).

Test case that now works but used to fail:
```
mx1 = MaskedArray([1.], mask=[True])
mx2 = MaskedArray([1., 2.])
mx = MaskedArray([mx1, mx2], mask=[False, True])
mx[0]
```