o do not drop entries "failsafe" and "linux-nonfb" when removing a kernel

- bootloader-config: 
  o configure ide-controller in modprobe.conf for upgrading to kernels 
    with modularized ide drivers

  o do create /boot/initrd-xxx.img when there is no bootloader 
    (#30771 comment #21)

(to have simpler dependencies between modules, esp. have some modules only required by diskdrake):

- move some functions from fs to fs::mount
  (most keep their name, except mount_part and mount_usbfs)
- move formatMount_part and formatMount_all from fs to fs::format

- move some functions from fs to fs::wild_device
  (part2wild_device_name -> fs::wild_device::from_part)
  (subpart_from_wild_device_name -> fs::wild_device::to_subpart)
  (analyze_wild_device_name -> fs::wild_device::analyse)

- formatMount_part(), formatMount_all(), fs::mount::part() don't take a prefix anymore
  the current situation was quite muddy
  we now rely on fs::get::mntpoint_prefixed() which will maybe depend on a field in $part
  for now, we mount every part in chroot, it seems to be what's wanted

- fs::format::part() now expect $all_hds instead of $raids

- fs::type::carryRootLoopback is now fs::get::carry_root_loopback()
- in fs::loopback, most functions don't want a prefix anymore

- use LABEL=... if preferred