ENH: ma.asarray() and ma.asanyarray() will pass through input of the correct type.

If x is of type MaskedArray for ma.asarray(x) or any subtype of
MaskedArray for ma.asanyarray(x), these functions will simply return x.
This makes them consistent with their numpy counterparts.

Closes gh-4043.
BUG: Fixed mask_rowcols().

Previous implementation relied on ma.asarray() to always create
a new object.

See gh-4043.
ENH: Make output of get_atlas_info conditional on system_info.verbosity
MAINT (API?): organize npyio.recfromcsv defaults

Organizes the default kwargs in recfromcsv. Changes two undocumented
kwargs behaviors:

*  previously, if a user set `names=None`, it was ignored and replaced
   with `names=True`
*  the `dtype` kwarg was ignored. If `update` was given, it was used as
   `dtype`, and if not, None was used. We can retain the `update` behavior
 by using `kwargs.setdefault("dtype",kwargs.get('update', None))`.
  This Closes #311 .
TST: Added regression test for recfromcsv dtype error, as suggested by @hpaulj
DOC: npyio.recfromcsv keyword argument changes

Added a note to recfromcsv about the `dtype` keyword,
as suggested by @hpaulj. Also added a note to the release notes,
about the change in the `update` keyword, as suggested by @charris.
BUG: Fixes gh-2208, alignment in subarrays
ENH: improve PyArray_Nonzero for sparse bool masks

we already count the number of true elements so we can decide when its
sparse and use faster (4-byte) vectorized npy_memchr.
Merge pull request #4370 from juliantaylor/where-improve

ENH: improve PyArray_Nonzero for sparse bool masks
ENH: Explicitly use __eq__ in assert_equal(a,b)

Fixes #2552. Changes primary test expression in function.
Merge pull request #4471 from meltingwax/meltingwax/2552-r2

ENH: Explicitly use __eq__ in assert_equal(a,b)
BUG: prevent nonzero memchr from running out of bounds
Merge pull request #4474 from juliantaylor/nonzero-bug

BUG: prevent nonzero memchr from running out of bounds
when initialize a vectorize object, always set self._ufunc to None first. fix #3285
MAINT: add NPY_BEGIN_THREAD_NDITER and remove unnecessary needs_api checks

the thread variable is initialized to NULL and checked by the end macro
so the needs_api check is redundant.
ENH: release gil for nonzero
ENH: Implemented ma.append

Fixes #2219.
ENH: release gil for np.take and np.arange

implies adapting check_and_adjust_index to allow threadsafe error
reporting.
ENH: release gil for np.packbits and np.unpackbits
BUG: add missing gufunc failure return values and missing malloc fail check