data journal parameters in README and fixed sh_notify first_boot script

README

+## Set data to journaled
+sudo tune2fs -o journal_data /dev/XXX
+# then in /etc/fstab add 
+data=journal
+# to the mount options
+
 ==== Ubuntu Installation ======
 1.) Create a squashfs filesystem with cubic
 

modules/common/files/first_boot_sh_notify.sh

+#!/bin/bash
+
 pipe=/tmp/first_boot_status
 
 if [[ -p $pipe ]]; then