make .dak files world-readable

make .dak files world-readable

2008-09-13  Philipp Kern  <pkern@debian.org>

        * dak/queue.py (dump_vars): make .dak u,g=rw,o=r; James'
        assumption (as stated in 2002-05-18's ChangeLog entry)
        was that people will use the information therein albeit
        it is "just" a duplication of information present in
        other control files; people should still not use it
        as source of information but access to those files makes
        dak debugging easier and there is no leak of sensitive
        information involved

Signed-off-by: Philipp Kern <pkern@debian.org>