DOC: Fix misleading description of random_sample in numpy.random docstring.
Merge pull request #3921 from mdickinson/doc-numpy-random-fixes

DOC: Fix misleading description of random_sample in numpy.random docstring.
BUG: core: ensure __r*__ has precedence over __numpy_ufunc__

Add a special case to the implementation of ndarray.__mul__ et al. that
refuses to work on other objects that are not ndarray subclasses and
implement both __numpy_ufunc__ and __r*__.

This way, execution passes first to the custom __r*__ method, which
makes it possible to have e.g. __mul__ and np.multiply do different
things.

Additionally, disable one __array_priority__ special case handling when
also __numpy_ufunc__ is defined.
Merge pull request #3856 from pv/op-before-ufunc

BUG: core: ensure __r*__ has precedence over __numpy_ufunc__
MAINT: io: handle a bad fmt argument in savetxt by raising a ValueError.
BUG: #2052 del scalar subscript causes segfault

Fixes issue #2052, where attempting to delete a scalar field causes a
segfault. Returns ValueError instead, like when attempting to delete an
array element.

Also added a test for this bug.
BUG: wrong boundary check in unrolled memchr
Merge pull request #3953 from WarrenWeckesser/savetxt-bad-fmt-error

MAINT: io: handle a bad fmt argument in savetxt by raising a ValueError.
Merge pull request #3954 from juliantaylor/memchr-bug

BUG: wrong boundary check in unrolled memchr
Merge pull request #3952 from JStech/issue_2052

BUG: #2052 del scalar subscript causes segfault
ENH: Attempt to rewrite the index parsing.

Some optimizations still missing.
WIP: Speed improvements by using EXTERNAL_LOOP
WIP,TST: Fix tests to match new behaviour
WIP: use fast_take and fix Deprecations
WIP,TST: Small fixes for the tests
WIP: bug fixes and field oder access change
WIP,TST: Fixup python3 tests
WIP: fix field order; And MapIterNext iteration end
WIP,TST,DOC: tiny fix

maybe triggers Travis too...
WIP: Move Ellipsis setting check and clear warnings