Extending list of parts doesn't include extended parts
If you extend a configuration file and add *more* parts to be constructed when launching Buildout, the expected behavior is to have all parts from our configuration file plus extended parts to be installed.
This used to work with zc.buildout < 1.4.0 but the 1.4.0 release has broke this behavior. I tracked down this problem to the merge of the 'tlotze-
I attached a test file which exposes the bug.