ubuild: add support for initramfs_rootfs_dir, see readme
specs: add initramfs_rootfs_dir to base.beaglebone.header
build.include: print the value of ${UBUILD_INITRAMFS_ROOTFS_DIR}
scripts: add fixrtc nocompcache noswap to BeagleBone u-boot cmdline
rootfs: minor cleanup in /etc/init.d/rcS
build.include: define global variable WORK_INITRAMFS_ROOTFS_DIR
initramfs.include: finalize initramfs_generate(), add support for WORK_INITRAMFS_ROOTFS_DIR
scripts: pre_build: rsync WORK_INITRAMFS_ROOTFS_DIR from initramfs_rootfs_dir=
scripts: post_build_initramfs: properly configure inittab and securetty for both rootfss