zc.buildout logger.  This reduces noise in the output.  This change
was so far reaching, I decided to go ahead and clean up lots of log
messages, adding some missing periods and adding quotes around
requirement strings and file paths.

in easy_install.py, added logging to show why distributions are added
in verbose mode and removed recusive code to show requirement chains
when errors occurred.

  an empty configuration file and then bootstraps.

- Except when using the new init command, it is now an error to run
  buildout without a configuration file.

- 75607: buildout should not run if it creates an empty buildout.cfg

setuptools requires that file urls that point to directories must
end in a "/".  Added a workaround.

  install and update methods.

- 59270: Buggy recipes can cause failures in later recipes via chdir

Also updated a test to reflect logging of script installation.

api to help clean up created paths when errors occir in recipe install
and update methods.

Made sure buildout exited with a non-zeo exit status when errors
occurred.

https://bugs.launchpad.net/zc.buildout/+bug/71353

Now use  system setuptools  if it is  available.  This can  also speed
bootstrapping,  since we  don't need  to download  setuptools  in more
cases.

https://bugs.launchpad.net/zc.buildout/+bug/105081.

packages that can't be found or that cause version conflicts.

packages that can't be found or that cause version conflicts.

Fixed a renormalizer to prevent spurious test failures,

packages that can't be found or that cause version conflicts.

Download caches didn't work on mac os x if directories in the download
cache path were symbolic links.

This led to a pretty major refactoring.

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It wasn't possible to give options on the command line for sections
not defined in a configuration file.

  to avoid database corruption when a user breaks out of a buildout
  with control-c.

- Don't save an installed database if there are no installed parts or
  develop egg links.

sections.