Cont. #135: Documented /admin; shortened /ban.

(Also stripped an old console.log call from it.)
Fix #120: /affiliate command.

This adds a modified variant of the /ban command
that accepts any affiliation type.

For UI reasons, the /ban command remains intact and
the only way to set an affiliation to "outcast".

("/affiliate none" and "/unban" have the same effect, however.)