does it for easy-install:

- require the download cache (but not namespace directories) to be an
  existing directory in order to catch configuration bugs

- made relative download cache paths refer to the buildout directory

  path and a flag indicating whether the downloaded copy is a temporary file
- use this flag to clean up temporary files both when downloading extended
  configuration files and in the tests

Conflicts:
	CHANGES.txt
	src/zc/buildout/buildout.py

  could be inserted into sys.path if a relative path was used to run
  the generated script.

Also fixed some spurious failures in the bootstrap test.

fixed test, so it does not break when using python 2.6 (previously a deprecation warning was displayed there inside the test output)

``zc.buildout.testing.buildoutSetUp`` installs a new handler in the python root logging facility. This handler is now removed during tear down as it might disturb other packages reusing buildout's testing infrastructure.

On Mac OS X the path returned by tempfile.mkdtemp is not the real path.
This makes the realtive_path test of easy_install.txt failing.
Calling os.path.realpath on the base directory fixed this testfailure for python 2.4 - 2.6.

to see that a file removed by a subprocess was actually removed.
Added logic to wait for the file to disappear. :/

Whitespace cleanup. (Although there are a few required trailing white
spaces in buildout.txt.

locations when generating scripts.

itself always uses it.

Remive the build directiory before building to make sure we're clean
when we witch Python versions.

in scripts when both the script and the eggs have a common base directory.