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.

this.

in site-packages.

isn't really stable (failing tests, hanging test)

setuptools in site-packages.  For now, the tests should pass whether
or not setuptools is in site-packages.

A better fix would be to control site-packages in the tests, or,
better yet, to change buildout to ignore site-packages.

o Avoids deprecation warnings in Python 2.6.  See:

  http://docs.python.org/library/subprocess.html#replacing-os-popen-os-popen2-os-popen3

be generated for all required eggs in addition to the eggs named
specifically.

The implementation is short and simple, but testing it required
changes in a lot of places.