Revert "cleaning up repo"

This reverts commit a3bb2995c48f2b923a0b3dd75bbd07cc24e4d296.
Revert "remove autodirstack commands and add noclobber"

This reverts commit 14b8ca1a459c9795f59580264c37464d6e4d4a6f.
Revert "revert the removal of autopushd etc"

This reverts commit c14339120876506c12eef86c99bcad9ab6ba4ba5.