2.2.0: Auto merge of #450 - kbknapp:issue-416, r=kbknapp

v2.2.0 (2016-03-15)

Features

• Help Message: can auto wrap and aligning help text to term width (e36af026, closes #428)
• Help Subcommand: adds support passing additional subcommands to help subcommand (2c12757b, closes #416)
• Opts and Flags: adds support for custom ordering in help messages (9803b51e)
• Settings: adds support for automatically deriving custom display order of args (ad86e433, closes #444)
• Subcommands: adds support for custom ordering in help messages (7d2a2ed4, closes #442)

Bug Fixes

• From Usage: fixes a bug where adding empty lines werent ignored (c5c58c86)

Documentation

• Groups: explains required ArgGroups better (4ff0205b, closes #439)