- split dump_boot into split_boot + unpack_ramdisk and write_boot into repack_ramdisk + flash_boot
- fully backwards compatible as dump_boot and write_boot still exist and call these new functions (i.e. no changes needed to anykernel.sh)
- those that wish to do zImage-only AK2 packages can now use split_boot intead of dump_boot and and flash_boot instead of repack_ramdisk in their anykernel.sh
- add failsafe check for failed boot-new.img creation to ensure abort before wiping target partition in edge cases