MFC r314705,r315406,r315407,r316025,r316082,r316731:

Add macOS 10.12
NetBSD 7.1 release added.
Indentation for the DragonFlyBSD trunk fixed, EoL whitespace removed.
macOS 10.12 release date added.
DragonFly BSD 4.8.0 release added.
OpenBSD 6.1 release added.