Added restore of btrfs subvolumes in restore mode (bnc #908011)

In oem recovery (restore) mode a new function named
restoreBtrfsSubVolumes will be called if the root filesystem
is btrfs based. The function will restore the configured
subvolumes back to the factory state
Fixed recovery of EFI bootdata

+ restore EFI module provided by the rpm package. The one kiwi
  created is specific to the uuid of the root filesystem which
  changes on factory restore.

+ make sure correct linux/linuxefi and initrd/initrdefi commands
  are used in recovery grub config by checking against grub_platform
  to allow recovery in BIOS and EFI mode

+ make sure mkfs.fat exists in the initrd to allow recovery of
  EFI fat partition, actually implement recovery of EFI fat
  partition
- v7.02.10 released