Update distribution guide and archive ez_setup doc

This adds a simple introductory guide to the modern way to distribute
`setuptools`-based projects with a link to the Python packaging
tutorial.

Rather than delete the old `ez_setup` information, it has been moved to
a separate archive for people who want to use it as a historical
reference.

docs/ez_setup.txt

+:orphan:
+
+``ez_setup`` distribution guide 
+===============================
+
+Using ``setuptools``...  Without bundling it!
+---------------------------------------------
+
+.. warning:: **ez_setup** is deprecated in favor of PIP with **PEP-518** support.
+
+.. _ez_setup.py: https://bootstrap.pypa.io/ez_setup.py
+
+.. _EasyInstall Installation Instructions: easy_install.html
+
+.. _Custom Installation Locations: easy_install.html
+
+Your users might not have ``setuptools`` installed on their machines, or even
+if they do, it might not be the right version.  Fixing this is easy; just
+download `ez_setup.py`_, and put it in the same directory as your ``setup.py``
+script.  (Be sure to add it to your revision control system, too.)  Then add
+these two lines to the very top of your setup script, before the script imports
+anything from setuptools:
+
+.. code-block:: python
+
+    import ez_setup
+    ez_setup.use_setuptools()
+
+That's it.  The ``ez_setup`` module will automatically download a matching
+version of ``setuptools`` from PyPI, if it isn't present on the target system.
+Whenever you install an updated version of setuptools, you should also update
+your projects' ``ez_setup.py`` files, so that a matching version gets installed
+on the target machine(s).
+
+(By the way, if you need to distribute a specific version of ``setuptools``,
+you can specify the exact version and base download URL as parameters to the
+``use_setuptools()`` function.  See the function's docstring for details.)
+
+
+What Your Users Should Know
+---------------------------
+
+In general, a setuptools-based project looks just like any distutils-based
+project -- as long as your users have an internet connection and are installing
+to ``site-packages``, that is.  But for some users, these conditions don't
+apply, and they may become frustrated if this is their first encounter with
+a setuptools-based project.  To keep these users happy, you should review the
+following topics in your project's installation instructions, if they are
+relevant to your project and your target audience isn't already familiar with
+setuptools and ``easy_install``.
+
+Network Access
+    If your project is using ``ez_setup``, you should inform users of the
+    need to either have network access, or to preinstall the correct version of
+    setuptools using the `EasyInstall installation instructions`_.  Those
+    instructions also have tips for dealing with firewalls as well as how to
+    manually download and install setuptools.
+
+Custom Installation Locations
+    You should inform your users that if they are installing your project to
+    somewhere other than the main ``site-packages`` directory, they should
+    first install setuptools using the instructions for `Custom Installation
+    Locations`_, before installing your project.
+
+Your Project's Dependencies
+    If your project depends on other projects that may need to be downloaded
+    from PyPI or elsewhere, you should list them in your installation
+    instructions, or tell users how to find out what they are.  While most
+    users will not need this information, any users who don't have unrestricted
+    internet access may have to find, download, and install the other projects
+    manually.  (Note, however, that they must still install those projects
+    using ``easy_install``, or your project will not know they are installed,
+    and your setup script will try to download them again.)
+
+    If you want to be especially friendly to users with limited network access,
+    you may wish to build eggs for your project and its dependencies, making
+    them all available for download from your site, or at least create a page
+    with links to all of the needed eggs.  In this way, users with limited
+    network access can manually download all the eggs to a single directory,
+    then use the ``-f`` option of ``easy_install`` to specify the directory
+    to find eggs in.  Users who have full network access can just use ``-f``
+    with the URL of your download page, and ``easy_install`` will find all the
+    needed eggs using your links directly.  This is also useful when your
+    target audience isn't able to compile packages (e.g. most Windows users)
+    and your package or some of its dependencies include C code.
+
+Revision Control System Users and Co-Developers
+    Users and co-developers who are tracking your in-development code using
+    a revision control system should probably read this manual's sections
+    regarding such development.  Alternately, you may wish to create a
+    quick-reference guide containing the tips from this manual that apply to
+    your particular situation.  For example, if you recommend that people use
+    ``setup.py develop`` when tracking your in-development code, you should let
+    them know that this needs to be run after every update or commit.
+
+    Similarly, if you remove modules or data files from your project, you
+    should remind them to run ``setup.py clean --all`` and delete any obsolete
+    ``.pyc`` or ``.pyo``.  (This tip applies to the distutils in general, not
+    just setuptools, but not everybody knows about them; be kind to your users
+    by spelling out your project's best practices rather than leaving them
+    guessing.)
+
+Creating System Packages
+    Some users want to manage all Python packages using a single package
+    manager, and sometimes that package manager isn't ``easy_install``!
+    Setuptools currently supports ``bdist_rpm``, ``bdist_wininst``, and
+    ``bdist_dumb`` formats for system packaging.  If a user has a locally-
+    installed "bdist" packaging tool that internally uses the distutils
+    ``install`` command, it should be able to work with ``setuptools``.  Some
+    examples of "bdist" formats that this should work with include the
+    ``bdist_nsi`` and ``bdist_msi`` formats for Windows.
+
+    However, packaging tools that build binary distributions by running
+    ``setup.py install`` on the command line or as a subprocess will require
+    modification to work with setuptools.  They should use the
+    ``--single-version-externally-managed`` option to the ``install`` command,
+    combined with the standard ``--root`` or ``--record`` options.
+    See the `install command`_ documentation below for more details.  The
+    ``bdist_deb`` command is an example of a command that currently requires
+    this kind of patching to work with setuptools.
+
+    Please note that building system packages may require you to install
+    some system software, for example ``bdist_rpm`` requires the ``rpmbuild``
+    command to be installed.
+
+    If you or your users have a problem building a usable system package for
+    your project, please report the problem via the mailing list so that
+    either the "bdist" tool in question or setuptools can be modified to
+    resolve the issue.
+
+Your users might not have ``setuptools`` installed on their machines, or even
+if they do, it might not be the right version.  Fixing this is easy; just
+download `ez_setup.py`_, and put it in the same directory as your ``setup.py``
+script.  (Be sure to add it to your revision control system, too.)  Then add
+these two lines to the very top of your setup script, before the script imports
+anything from setuptools:
+
+.. code-block:: python
+
+    import ez_setup
+    ez_setup.use_setuptools()
+
+That's it.  The ``ez_setup`` module will automatically download a matching
+version of ``setuptools`` from PyPI, if it isn't present on the target system.
+Whenever you install an updated version of setuptools, you should also update
+your projects' ``ez_setup.py`` files, so that a matching version gets installed
+on the target machine(s).
+
+(By the way, if you need to distribute a specific version of ``setuptools``,
+you can specify the exact version and base download URL as parameters to the
+``use_setuptools()`` function.  See the function's docstring for details.)
+
+.. _install command:
+
+``install`` - Run ``easy_install`` or old-style installation
+============================================================
+
+The setuptools ``install`` command is basically a shortcut to run the
+``easy_install`` command on the current project.  However, for convenience
+in creating "system packages" of setuptools-based projects, you can also
+use this option:
+
+``--single-version-externally-managed``
+    This boolean option tells the ``install`` command to perform an "old style"
+    installation, with the addition of an ``.egg-info`` directory so that the
+    installed project will still have its metadata available and operate
+    normally.  If you use this option, you *must* also specify the ``--root``
+    or ``--record`` options (or both), because otherwise you will have no way
+    to identify and remove the installed files.
+
+This option is automatically in effect when ``install`` is invoked by another
+distutils command, so that commands like ``bdist_wininst`` and ``bdist_rpm``
+will create system packages of eggs.  It is also automatically in effect if
+you specify the ``--root`` option.
+
+
+``install_egg_info`` - Install an ``.egg-info`` directory in ``site-packages``
+==============================================================================
+
+Setuptools runs this command as part of ``install`` operations that use the
+``--single-version-externally-managed`` options.  You should not invoke it
+directly; it is documented here for completeness and so that distutils
+extensions such as system package builders can make use of it.  This command
+has only one option:
+
+``--install-dir=DIR, -d DIR``
+    The parent directory where the ``.egg-info`` directory will be placed.
+    Defaults to the same as the ``--install-dir`` option specified for the
+    ``install_lib`` command, which is usually the system ``site-packages``
+    directory.
+
+This command assumes that the ``egg_info`` command has been given valid options
+via the command line or ``setup.cfg``, as it will invoke the ``egg_info``
+command and use its options to locate the project's source ``.egg-info``
+directory.

docs/index.txt

@@ -17,9 +17,10 @@ Documentation content:
    :maxdepth: 2
 
    setuptools
-   easy_install
    pkg_resources
    python3
    development
    roadmap
+   easy_install
+   ez_setup
    history