ramdisk: more compatibility fixes mirrored from AnyKernel2 for 4.2+
- revert init.superuser.rc to basic and handle SuperSU via bootscript.
- add back ext4 userdata fstab mount opts workaround for older init binaries (legacy Android)
- new f2fs userdata fstab mount opts workarounds, as above.
- fix oops (forgotten ;) breaking dvbootscript execution.
- clean up systemui and lmk whitelist waits and pid handling.