Update MirOS bsd4grml to 20091024 and use it to chainload GRUB2 from SYSLINUX

• Update MirOS bsd4grml to 20091024 (ldbsd.com and ldbsd.txt only)
• templates/boot/isolinux/{addons,syslinux}.cfg: Use new ldbsd.com
  feature (command line) to chain into GRUB2 directly from ISOLINUX
  or SYSLINUX without an intermediate interactive/menu prompt, as
  requested by Uli Dangel and Mika Prokop

Signed-off-by: Thorsten Glaser <tg@mirbsd.org>