* GitHub is removing the underlying API used to implement the `login` command. Since the general consensus seems to be that relatively nobody currently uses this command (in favor of explicit token passing), support was simply removed for interactive login. If a future need arises, this command should be reimplemented via OAuth Device Auth Grants.
* login or role login commands now produce a fatal error with a descriptive message
* updated 2.10 and 2.11 porting guide entries
* remove dead code/config, update messages and porting guides
