file_readable_permissions
makethumbs makes files world readable during
its execution. The idea is that you may have a restrictive
umask setting, but the files may need to be world
readable to be visible via the web. makethumbs'
chmod'ing behavior can be disabled entirely
(via change_file_permissions
) or you can tweak
this setting.
The value of file_readable_permissions
is something
that can be passed to chmod on the command line.