POSIX says an empty entry in CDPATH shall not result in the new directory
being printed, while any non-empty entry shall result in the new directory
being printed, including ".". Therefore, the value of CDPATH should almost
always start with a colon, not dot and colon.
Our sh does not print the name for empty entries as well as "." entries.
MFC after: 1 week
these days, and the average user expects ^A and arrow keys to work, however
if they know nothing of editing modes, they will think sh(1) just sucks. It
is likely that because of defaults on most systems and with most shells that
anyone who actually wants vi(1) editing mode will have 'set -o vi'. This
won't affect existing accounts, this way, of course. Only accounts with
.shrc from new etc/skel will be affected. This is much better than making
the change in sh(1).
