Features:
- New hub pr list --format fields %pS and %pC for PR state and color
- %pS: "open", "draft", "merged", or "closed"
- %pC: green, gray, purple, or red
- Have commands with rich output respect the --color flag
- default: --color=auto
- --color is equivalent to --color=always
- --color=never disables color for TTYs
Fixes:
- Make man pages parseable with whatis
- Make hub checkout work independently of remote refspec