mozilla/configman — pull request #23 by peterbe (2012-01-27 00:18:54+00:00)
Title: values_source_list doesn't change to default values unless it's passed i...

...n as None.

If you use `ConfigurationManager(values_source_list=[])` it will not set up the defaults.

Relevant to prevent it from picking up weird commandline or environement variables in, for example, unit test runs.