Revert "fixes #141 wordsmithing on canputnext(9F) needed"

This reverts commit a65b27e83dde8ffdcdcc226fd970427f54cd9206.
(Accidentally merged in unrelated changes for mv/cp.)
fixes #141 wordsmithing on canputnext(9F) needed
fixes #143 warnings in mv.c are real issues
fixes #142 ln man page has various errors
fixes #140 POSIX: mv should not prompt if -i missing and !istty(stdin)
fixes #73 make cp, mv, ln XPG4 behaviors default