svn-git: Use binmode for reading/writing binary rev maps
Otherwise, there is a possible interaction with UTF-8 locales in
combination with PERL_UNICODE, resulting in "inconsistent size: 40" or
"read:"-type errors.
See also:
perldoc -f binmode
<http://perldoc.perl.org/perl581delta.html#UTF-8-no-longer-default-under-UTF-8-locales>
Signed-off-by: Michael Weber <michaelw@foldr.org> Acked-by: Eric Wong <normalperson@yhbt.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>