Post-mortem debug ability in cloud

We should add a process to be executed AFTER the main process in a pod terminates that preserves information useful for debugging, if the main process terminates abnormally.

We can use sentinel file to determine whether the main process was terminated cleanly.

Information to gather includes:
Core files (optional)
Extracted info from core files - all stacks, variables etc
Syslog info
Full log (may be more than goes to ELK)
Spill files that were the input to the current graph (optional)