(CLEANUP_CWD, CLEANUP): Remove.

(CLEANUP_CWD, CLEANUP): Remove.
(make_dir_parents): Revamp to avoid need for CLEANUP_CWD, CLEANUP.
If the file already exists but is not a directory, don't bother
to try to make its parents.
Close potential file descriptor leak if we can't chdir("/") (!).
Don't always return true if chdir($PWD) fails; return true only
if the requested action was done successfully (except for the
chdir($PWD)).
Don't log final directory unless we actually made it.
Refactor to avoid duplicate code to fix up permissions.
Don't attempt to fix up parent permissions if chdir($PWD) fails.