Fixed a mistake in linalg.eig() documentation.
DOC: Fixes for doc/source/user/basics.io.genfromtxt.rst.

Add missing part of usecols negative index explanation and other
minor redaction fixes.
MAINT: Cleanup doc/source/user/basics.io.genfromtxt.rst.

Remove trailing whitespace.
Break long lines.
Fix some indentation.
Use the `::` directive to indicate interactive examples.
Fix doc typo
ENH: inv/solve work with empty inner and others empty outer array

This makes the inverse of a 0x0 array simply be 0x0 again. It
also modifies the no-empty array check in favor of a no-empty
*inner* array, since the gufuncs seem to handle the other case
fine.
MAINT: runtests: make it work on Fedora
Merge pull request #3572 from pv/fix-runtests

MAINT: runtests: make it work on Fedora
ENH: For smaller array, added macro NPY_BEGIN_THREADS_THRESHOLDED in ndarraytypes.h
Avoiding NPY_BEGIN_THREADS for small arrays, can speed-up trivial_three_operand_loop by 5%.
As releases of GIL, then quickly restoring just after small operation doesn't benefit.
Merge pull request #3568 from mspacek/patch-1

Fix doc typo
BUG: Boolean assignment allowed writing to 0-sized array

This was because of the assumption that broadcasting works
if the dimension is not > 1, but correct is != 1.

Adepted from a patch provided by prossahl.

Closes gh-3458.
MAINT: fix typo in npy-format.txt
Merge pull request #3576 from mspacek/patch-3

MAINT: fix typo in npy-format.txt
Merge pull request #3575 from seberg/issue-3458

BUG: Boolean assignment allowed writing to 0-sized array
Merge pull request #3521 from arinkverma/gsoc_performance

ENH: Avoiding NPY_BEGIN_THREADS for small arrays can speed-up trivial_three_operand_loop by 5%
Merge pull request #3565 from charris/documentation-fixes

Documentation fixes for `basics.io.genfromtxt.rst` and `creation.py`
Merge pull request #3513 from seberg/0d-linalg

ENH: inv/solve work with empty inner and others empty outer array
ENH: Added test cases to ensure the behavior of integer as it is.
There is a need to add test case which ensure and maintain the behaviour
of integer. As per pr #3567, which speed up integer scalar's operations
by avoiding the conversion of integer to NumPy Scalar.
ENH: improve numpy.all()/any()

Unroll the loop once and use pminub/pmaxub to save a slow pmovmskb
instruction. Improves performance by 50% on some AMD chips.
Also add a pure libc path using memcmp and memchr for non amd64 systems.
The libc path can be faster with a very modern cpu and libc version,
e.g. an i7 with glibc 2.17 is about 20% faster than our code but many
other tested platforms are much slower (2.12 xeon, core2duo) or same
speed (2.17 phenom).
The numpy code can be removed in future when faster libc versions and
cpus are more commonly available.
MAINT: move npy_is_aligned to common.h

also make it and some other alignment operators a bit faster by using
unsigned integers and bitwise and if possible.
Make use of npy_is_aligned in _IsAligned too.
ENH: add NPY_LIKELY and NPY_UNLIKELY macros for branching hints

Use it for npy_is_aligned expecting alignments of the power of two.
Cuts down the time spent in _IsAligned by the testsuite relative
to the rest of multiarray.so from 0.6% to 0.4%