Improve handling of hived responses in entrypoint script
Now the entrypoint script should behave as follows:
- exit with 0 code when hived finishes its work nominally (e.g.
--stop-before-sync
). - exit with 0 code when hived is interrupted with direct SIGINT or SIGTERM
- exit with 0 code when Ctrl-C is issued in console attached to the script shell
- exit with error code when hived receives SIGKILL
- exit with error code in case of failure of other command run by the script