Yelp/mrjob — pull request #475 by irskep (2012-06-12 19:27:10+00:00)
Title: --conf-path can be used multiple times

Fixes #420.

Changes the internal type of `conf_path` to a list so that `--conf-path` can be used more than once on the command line. Also expands the documentation.

I had to use optparse's callback feature to handle `--no-conf` and default values properly. The idea is to keep the default types the same (`None` for 'go find it' and `False` for none at all) but make it a list if any paths are specified.