po: update cs.po (from translationproject.org)
po: update da.po (from translationproject.org)
po: update de.po (from translationproject.org)
po: update ja.po (from translationproject.org)
po: update pt_BR.po (from translationproject.org)
po: update zh_CN.po (from translationproject.org)
po: merge changes

Signed-off-by: Karel Zak <kzak@redhat.com>