dbus - security update

This updates fixes multiple (local) denial of services discovered by Alban
Crequy and Simon McVittie.

• CVE-2014-3477
  Fix a denial of service (failure to obtain bus name) in
  newly-activated system services that not all users are allowed to
  access.
• CVE-2014-3638
  Reduce maximum number of pending replies per connection to avoid
  algorithmic complexity denial of service.
• CVE-2014-3639
  The daemon now limits the number of unauthenticated connection slots
  so that malicious processes cannot prevent new connections to the
  system bus.

For Debian 6 Squeeze, these issues have been fixed in dbus version 1.2.24-4+squeeze3