Fixes and features:
- config file syntax is now easier to override or extend using the new constructor arg:
config_file_parser(via merged PR #28 - thanks @lahwaacz ) - support for python 2.6 (via merged PR #18 - thanks @kuba )
- replace dashes with underscores in env. var names when using the auto-env-var feature (via merged PR #29 - thanks @helgi )