TST: Add tests for constants.

Test the values of np.pi, np.e, and np.euler_gamma to make sure
they are correct to relative tolerance 1e-15.
fix array interface documentation links
Merge pull request #2873 from sandrotosi/master-numpy.org

DOC: fix array interface documentation links
DOC: Add missing minus sign

The int64 data type allows numbers from -9223372036854775808 to
9223372036854775807. The minus sign was missing.
Merge pull request #2874 from certik/fixdoc

DOC: Add missing minus sign
TST: skip floating point warning test failures on ARM.  Closes gh-413.
MAINT: remove painful to look at exec statement from np.errstate test.
TST: remove Python 2.4 and 2.5 testing from Travis config.

Done because for 1.8 we're not supporting these Python versions anymore,
and this PR break 2.4 compatibility.
BUG: Fix CheckStrides and strides setter checks for available memory

This changes the logic of PyArray_CheckStrides to really check the
full extent the new array will have. It also changes the stride
setting to calculate the full real extent of the underlying array
without assuming (usually correctly) that the strides of the base
array are regular.

Add some tests for cases that previously failed.
This "closes Issue gh-2503"
Merge pull request #2879 from rgommers/issue-413-arm-failures

Fix ARM failures (gh-413)
MAINT: Move offset calculations into special function

Also adds a test to check offset calculation is correct when
setting strides for a base array with negative strides.
Fixed choice docstring, wrong default size

Commit acf7421128b9d974d5153759650b7aaee3c2efec introduced a change in the handling of the `size` argument but the docstring wasn't updated accordingly. This commit fixes the issue.
Merge pull request #2884 from Juanlu001/patch-1

Fixed choice docstring, wrong default size
BUG: Fix byteswapping for complex scalars

During a cleanup, the fast paths were invalidated because SIZEOF_LONGDOUBLE
was not defined anymore and needs to be replaced with NPY_SIZEOF_LONGDOUBLE.
The other SIZEOF macros still existed however so only complex long double
broke because it switched to the already broken fast path.

This commit fixes the fast path, and replaces all SIZEOF_ macros within
arraytypes.c.src with their corresponding NPY_SIZEOF_ macros.
Merge pull request #2886 from seberg/complex256-byteswap

BUG: Fix byteswapping for complex scalars
MAINT: Remove unneeded comment form arrayobject.h
MAINT: Remove unneeded include from ndarraytypes.h.
MAINT: Add some macros to noprefix.h

Some of these are probably new unprefixed macros, but adding them
makes for a bit more safety. The unprefixed macros will be deprecated
at some point, so this probably has no side effects.
MAINT: Gather NPY_SIZEOF* macros into one spot.
MAINT: Remove tabs from numpyconfig.h.