Merge pull request #493 from kbknapp/v2.4.0

v2.4.0 (2016-05-02)

Features

• Help: adds support for displaying info before help message (29fbfa3b)
• Required: adds allowing args that are required unless certain args are present (af1f7916)

Documentation

• hides formatting from docs (cb708093)
• required_unless: adds docs and examples for required_unless (ca727b52)

Bug Fixes

• Required Args: fixes issue where missing required args are sometimes duplicatd in error messages (3beebd81, closes #492)