Performance

--------------------------

* compile command: Add "pkg_only" option to benchmark.conf.
Add support for native libraries that are installed but not on path.
Patch by Robert Grimm.
* Update Travis configuration: use trusty image, use pip cache.
Patch by Inada Naoki.
* Upgrade tornado to 5.1.1.
Patch by Inada Naoki.
* Fix compile command on Mac OS: no program extension. Patch by Anthony Shaw.
* Update requirements:

* Chameleon: 3.4 => 3.6.1
* Django: 1.11.16 => 1.11.20
* Genshi: 0.7.1 => 0.7.2
* Mako: 1.0.7 => 1.0.9
* MarkupSafe: 1.0 => 1.1.1
* SQLAlchemy: 1.2.12 => 1.3.3
* certifi: 2018.10.15 => 2019.3.9
* dulwich: 0.19.6 => 0.19.11
* mercurial: 4.7.2 => 5.0
* mpmath: 1.0.0 => 1.1.0
* pathlib2: 2.3.2 => 2.3.3
* perf: 1.5.1 => 1.6.0
* psutil: 5.4.7 => 5.6.2
* six: 1.11.0 => 1.12.0
* sympy: 1.3 => 1.4
* tornado: 4.5.3 => 5.1.1

--------------------------

* python_startup: Add ``--exit`` option.
* Update requirements:

* certifi: 2017.11.5 => 2018.10.15
* Chameleon: 3.2 => 3.4
* Django: 1.11.9 => 1.11.16
* dulwich: 0.18.6 => 0.19.6
* Genshi: 0.7 => 0.7.1
* mercurial: 4.4.2 => 4.7.2
* pathlib2: 2.3.0 => 2.3.2
* psutil: 5.4.3 => 5.4.7
* SQLAlchemy: 1.2.0 => 1.2.12
* sympy: 1.1.1 => 1.3

* Fix issue 40 for pip 10 and newer: Remove indirect dependencies. Indirect
dependencies were used to install cffi, but Mercurial 4.0 doesn't depend on
cffi anymore.

--------------------------

* Fix inherit-environ: propagate to recursive invocations of ``performance``
in ``compile`` and ``compile_all`` commands.
* Fix the ``--track-memory`` option thanks to the update to perf 1.5.
* Update requirements

- certifi: 2017.4.17 => 2017.11.5
- Chameleon: 3.1 => 3.2
- Django: 1.11.3 => 1.11.9
- docutils: 0.13.1 => 0.14
- dulwich: 0.17.3 => 0.18.6
- html5lib: 0.999999999 => 1.0.1
- Mako: 1.0.6 => 1.0.7
- mercurial: 4.2.2 => 4.4.2
- mpmath: 0.19 => 1.0.0
- perf: 1.4 => 1.5.1 (fix ``--track-memory`` option)
- psutil: 5.2.2 => 5.4.3
- pyaes: 1.6.0 => 1.6.1
- six: 1.10.0 => 1.11.0
- SQLAlchemy: 1.1.11 => 1.2.0
- sympy: 1.0 => 1.1.1
- tornado: 4.5.1 => 4.5.3

--------------------------

* Change ``warn`` to ``warning`` in `bm_logging.py`. In Python 3, Logger.warn()
calls warnings.warn() to log a deprecation warning, so is slower than
Logger.warning().
* Add again the ``logging_silent`` microbenchmark suite.
* compile command: update the Git repository before getting the revision
* Update requirements

- perf: 1.3 => 1.4 (fix parse_cpu_list(): strip also NUL characters)
- Django: 1.11.1 => 1.11.3
- mercurial: 4.2 => 4.2.2
- pathlib2: 2.2.1 => 2.3.0
- SQLAlchemy: 1.1.10 => 1.1.11

--------------------------

* On the 2.x branch on CPython, ``compile`` now pass ``--enable-unicode=ucs4``
to the ``configure`` script on all platforms, except on Windows which uses
UTF-16 because of its 16-bit wchar_t.
* The ``float`` benchmark now uses ``__slots__`` on the ``Point`` class.
* Remove the following microbenchmarks. They have been moved to the
`pymicrobench <https://github.com/vstinner/pymicrobench>`_ project because
they are too short, not representative of real applications and are too
unstable.

- ``pybench`` microbenchmark suite
- ``call_simple``
- ``call_method``
- ``call_method_unknown``
- ``call_method_slots``
- ``logging_silent``: values are faster than 1 ns on PyPy with 2^27 loops!
(and around 0.7 us on CPython)

* Update requirements

- Django: 1.11 => 1.11.1
- SQLAlchemy: 1.1.9 => 1.1.10
- certifi: 2017.1.23 => 2017.4.17
- perf: 1.2 => 1.3
- mercurial: 4.1.2 => 4.2
- tornado: 4.4.3 => 4.5.1

--------------------------

* Create a new documentation at: http://pyperformance.readthedocs.io/
* Add "CPython results, 2017" to the doc: significant performance changes,
significant optimizations, timeline, etc.
* The ``show`` command doesn't need to create a virtual env anymore.
* Add new commands:

- ``pyperformance compile``: compile, install and benchmark
- ``pyperformance compile_all``: benchmark multiple branches and
revisions of Python
- ``pyperformance upload``: upload a JSON file to a Codespeed

* setup.py: add dependencies to ``perf`` and ``six`` modules.
* bm_xml_etree now uses "_pure_python" in benchmark names if the accelerator is
explicitly disabled.
* Upgrade requirements:

- Django: 1.10.6 -> 1.11
- SQLAlchemy: 1.1.6 -> 1.1.9
- mercurial: 4.1.1 -> 4.1.2
- perf: 1.1 => 1.2
- psutil: 5.2.1 -> 5.2.2
- tornado: 4.4.2 -> 4.4.3
- webencodings: 0.5 -> 0.5.1

* perf 1.2 now calibrates the number of warmups on PyPy.
* On Python 3.5a0: force pip 7.1.2 and setuptools 18.5:
https://sourceforge.net/p/pyparsing/bugs/100/