FruitOS version 0.0.4

• A/B root filesystems: /dev/mmcblk0p2 and /dev/mmcblk0p3
• using U-Boot to enable flipflop between two root filesystems
• using a custom initramfs-init
• new software packages:
  • fruit-agent
  • fruit-baselayout
  • fruit-initramfs
  • fruit-keys
  • fruit-rpi-bootloader
  • fruit-rpi-linux
  • fruit-rpi2-linux
  • fruit-u-boot
  • rpi-firmware