BUG: restore api for file npy_PyFile_Dup and npy_PyFile_DupClose

breaking the api breaks matplotlib build and pip installation.
Introduce npy_PyFile_Dup2 and npy_PyFile_DupClose2 as replacements
Merge pull request #4455 from juliantaylor/api-restore-1.8

restore npy_PyFile_Dup api for 1.8.x
BUG: Fix commutativity of {dot,multiply,inner}(scalar, matrix_of_objs)

Fixes #2469 and #4482. Relaxes fail condition to allow subtype as documented.
DOC: Add backport of gh-4483 to release notes.
Merge pull request #4501 from charris/backport-1.8-gh-4483

Backport 1.8 gh 4483
ENH: Backport scalarmathmodule.h.src from 1.9.0-devel.

This is needed in order to backport npyiter fixes.
BUG: Backport nditer fixes and tests.

This is mostly gh-4466, but other bits had to come with it to
make it work.
DOC: Document backport of gh-4466 in 1.8.1 release notes.
Merge pull request #4504 from charris/backport-1.8-gh-4466

Backport 1.8 gh 4466
BUG: Buffered stride was erroneously marked fixed (fixes #4485)
TST: Test for einsum/nditer fixed stride bug
DOC: Add gh-4502 to the 1.8.1 release notes.
Merge pull request #4506 from charris/backport-1.8-gh-4502

Backport 1.8 gh 4502
DOC: Update 1.8.1 release notes.

Document changes in nditer.
Merge pull request #4508 from charris/update-1.8.1-release-notes

DOC: Update 1.8.1 release notes.
TST: work around outdated travis boxes

run manual apt-get update to pick up the latest py3 security update
Merge pull request #4510 from charris/Backport-1.8-gh-4456

Backport-1.8-gh-4456.
BUG: Fix linspace for use with physical quantities

The fix for issue 3504 led to errors when using linspace with the quantities package. Multiplying with 1 instead of adding 0 prevents issues when using physical quantities.
Merge pull request #4511 from juliantaylor/quant-1.8

backport gh-4503 to 1.8
ENH: Make output of get_atlas_info conditional on system_info.verbosity