v1.7

• fixme : GRUB_BTRFS_SUBMENUNAME
• overhaul menu :
  1 - Add Show full path or only name of snapshots in grub-menu
  2 - New option in /etc/default/grub :
  GRUB_BTRFS_TITLE_FORMAT="p/d/n"
  (Custom title, shows/hides p"prefix" d"date" n"name" in grub-menu, separator "/", custom order available)
• translation update