jessevdk/go-flags — pull request #116 by mpobrien (2014-11-14 02:31:28+00:00)
Title: Add field for callback to handle unknown/unmapped options during parse

This is the follow-up from our discussion in https://github.com/jessevdk/go-flags/pull/111
Hope this matches what you had in mind. Let me know if you'd like to see any changes.