Added a configuration option that causes buildout to error if a
  version is picked. This is a nice safety belt when fixing all
  versions is intented, especially whan creating releases.

(This already-desired feature made it easier to write the test for
  the bug fix below. :)

Bug Fixed:

When installing from source releases, a version specification (via a
  buildout versions section) for setuptools was ignored when deciding
  which setuptools to use to build an egg from the source release.

151820: Add the distribution directory to sys.path when running
the setup.py script so that the setup.py script can import modules
from the distribution directory.

Fix verbose option handling of debug logging message

Now there's a buildout option (use-dependency-links) that allows you to 
disable setuptool dependency_links metadata.

When using a local find links or index, distributions weren't copied
 to the download cache.

Improved error message when no arguments are given to the setup
command.

The setup command no-longer requires a config file.

ref: https://bugs.launchpad.net/bugs/149352

  existing buildouts.  Use::

[buildout]
    prefer-final = true

to get the new policy.  The new policy will go into effect in
  buildout 2.

  both final and non-final versions satisfy a requirement, then the
  final version will be used even if it is older.  The normal way to
  override this for specific packages is to specifically require a
  non-final version, either specifically or via a lower bound.

- There is a buildout prefer-final version that can be used with a
  value of "false"::

prefer-final = false

To prefer newer versions, regardless of whether or not they are
  final, buildout-wide.

to work with recent change changes to use expanduser rather than
reading $HOME directly.

for versions if the given requirement had an upper limit and we
already had the distribution whos version was the upper limit.

Added simpler tested code that checks for the simpler case that teh
requirement is for a specific version and we already have that
version.  In general, specifying upper limits other than a single
version is kind of dumb, so it's not worth optimizing for that case.

Also rearranged some code to work with emacs python mode. :)

deterministic output by outputing all of standard output followed
by all of standard error.

Removed a test that was obsoleted by a setuptools improvement in
handling failed downloads.

Updated to reflect a change in bootstrapping. (I wonder why this
wasn't needed sooner.)