ms-sys: 2.5.1 -> 2.5.2; maintain

Changes:
  - Added german man page,
  - added support for Grub2 and Grub4Dos MBR,
  - added support for KolibriOS MBR and FAT32 boot record,
  - added support for ReactOS MBR, FAT32 and FAT16 BR,
  - added support for Rufus MBR,
  - added experimental support for large sectors ( > 512),
  - now possible to alter OEM ID of FAT and NTFS boot records.
  - now possible to alter Windows Disk Signature in MBR.