* origin/026:
docs: update Changelog for release.
Bump version for release.
issue #555: ansible: workaround ancient reload(sys) hack.
issue #554: mitogen_action_script fix
issue #554: fix Ansible 2.4 compatibility
issue #554: don't rely on tmp_path autoremoval in test.
issue #554: track and remove multiple make_tmp_path() calls.
docs: update Changelog.
docs: drastically simplify install/changelog.
issue #552: include process identity in log messages.
issue #550: update Changelog.
issue #550: parent: add explanatory comment.
issue #550: fix up TTY ioctls on WSL 2016 Anniversary Update
docs: update Changelog.
service: make service list optional.
docs: update Changelog; closes#548.
issue #548: always treat transport=smart as 'ssh' for mitogen_via=.
docs: better intro paragraph.
.ci: copy private key file to tempdir.
os_fork: more doc tweaks
os_fork: more doc tweaks
os_fork: yet more doc tidyup
os_fork: more doc tweaks
os_fork: clean up docs
.ci: import soak scripts.
.ci: allow containers for different jobs to run simultaneously
os_fork: python 3 fixes and tests.
issue #535: activate Corker on 2.4 in master too.
issue #535: update Changelog.
issue #535: wire mitogen.os_fork into Broker and Pool.
issue #535: parent: add create_socketpair(size=..) parameter.
issue #535: introduce mitogen.os_fork module and Corker class.
issue #535: docs: update Changelog
issue #535: service: support Pool.defer() like Broker.defer()
issue #535: core: unicode.encode() may take importer lock on 2.x
issue #535: docs: fix up Select doc
issue #535: docs: update Changelog.
issue #535: core/select: support selecting from Latches.
core: increase cookie field lengths to 64-bit; closes#545.
tests: ensure serialization restrictions are in effect
tests/bench: set process affinity in throughput.py.
docs: update copyright year.
docs: update Changelog.
core: Make Latch.put(obj=) optional.
docs: change 'unreleased' Changelog format and add a hint.
docs: update Changelog; closes#542.
issue #542: return of select poller, new selection logic
issue #542: .ci: move some tests to Azure and enable Mac job.
ansible: create stub __init__.py for sdist.
This is the most minimal change for what might be relatively minimal
edge case. Alternative is replacing reload(), but let's not do that yet.
Closes#555