dd: always sanitize mode of saved file

- we use O_CREAT as the argument for open() and man says:
    'The permissions of the created file are (mode & ~umask)'
- we want to set the required mode without mangling it by umask, thus we have to
  change file's mode by chmod
- related to trac#927

Signed-off-by: Jakub Filak <jfilak@redhat.com>
configure: fix dump dir mode help string

- related to trac#927

Signed-off-by: Jakub Filak <jfilak@redhat.com>
configure: change defaults to be compliant with /var/tmp/abrt

- default dump dir mode = 0660
- dump dump ownership template = user:abrt

- related to trac#927

Signed-off-by: Jakub Filak <jfilak@redhat.com>
rpm: preserve old configuration for <F17 and <REHL7

- default dump dir mode = 0640
- dump dir ownership template = abrt:user's group

- related to trac#927

Signed-off-by: Jakub Filak <jfilak@redhat.com>