Ensure sticky bit is set on all world-writable directories

# df --local -P | awk {'if (NR!=1) print $6'} | xargs -I '{}' find '{}' -xdev -type d 
-perm -0002 2>/dev/null | xargs chmod a+t

# df --local -P | awk {'if (NR!=1) print $6'} | xargs -I '{}' find '{}' -xdev -type d 
\( -perm -0002 -a ! -perm -1000 \) 2>/dev/null