initramfs.init: change /boot permissions and mount order
  since /boot now uses vfat, it is needed to mount it with umask=077 (permissions 700) for security reasons
  we umount /sys and /proc in initramfs before switch_root so that we don't need to modify rc.boot in write-hd-image-squash.sh
add service prereqs infrastructure and install services from packages.
  this allows to have less users installed by default, so services can install new users they need
  it also allows the creation of a read-only root by separating what the service needs from running the service
  install services from their respective packages instead of installing all services by default
add sshd metaservice that start openssh or dropbear
write-hd-image-squash.sh: use prereqs to setup rootfs
mdev.conf: rename the uucp group to serial
passwd/group: remove unneeded groups and users
wpa-supplicant: add a service file and default config
iw: remove unneeded CFLAGS from the libnl-tiny patch