sync/adjust LS_COLORS
    
    * coreutils-DIR_COLORS: sync with upstream
    (remove old Xiph formats, add m4a audio format).
    * coreutils-DIR_COLORS.256color: Likewise.
    Also sync with 8 color mode above, by removing
    the specific MULTIHARDLINK coloring, and
    giving MISSING symlink targets a red background.
    Also lighten the DIR and EXEC color a little
    (as discussed in bug 1196642)
    * coreutils-DIR_COLORS.lightbgcolor: Sync terminal
    types with other 2 databases above.