[Distutils] Release: pip 6.0 and virtualenv 12.0

[Donald Stufft]

I'm happy to announce the release of pip 6.0 and virtualenv 12.0.

A High level overview of what this brings:

* PEP 440 is fully implemented now and pip will use specifiers and the version
  selection logic as specified there.

* HTTP access will now be cached by default in pip, speeding up repeated
  downloads of the same file automatically.

* Randomized and secure build directories are used by default in most
  situations.

* Accessing an insecure origin (Invalid HTTPS or HTTP) by default is now
  deprecated. For HTTP this will continue to work in pip 6.0 but raise a
  warning and for HTTPS this will not work. You may use
  --trusted-host example.com to re-enable this on a per-host basis.

* Added per-virtualenv and a machine global configuration file, as well as
  support platform standard directories for configuration.

* Support environment markers inside of a requirements file.

* Support environment markers inside of a setuptools extra.

* Automatically retry failed HTTP requests.

* Greatly reduce the verbosity of the pip command by default.

* Updated virtualenv to have setuptools 8.2.1 and pip 6.0 bundled.

* Many many bugfixes and smaller changes.

As always please file any issues with either https://github.com/pypa/pip/issues
or https://github.com/pypa/virtualenv/issues.

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Donald Stufft
PGP: 7C6B 7C5D 5E2B 6356 A926 F04F 6E3C BCE9 3372 DCFA