logging: save logpyle DB on SIGTERM

[matthiasdiener]

Questions for the review:

• [ ] Is the scope and purpose of the PR clear?
  • [ ] The PR should have a description.
  • [ ] The PR should have a guide if needed (e.g., an ordering).
• [ ] Is every top-level method and class documented? Are things that should be documented actually so?
• [ ] Is the interface understandable? (I.e. can someone figure out what stuff does?) Is it well-defined?
• [ ] Does the implementation do what the docstring claims?
• [ ] Is everything that is implemented covered by tests?
• [ ] Do you see any immediate risks or performance disadvantages with the design? Example: what do interface normals attach to?

[majosm]

Works ok on lassen?

[matthiasdiener]

Works ok on lassen?

Yes, after https://github.com/illinois-ceesd/logpyle/pull/151. A simple way to try it out:

$ python -m mpi4py examples/wave.py & sleep 10 ; kill %1  # or kill -INT %1

The resulting *.sqlite file(s) should contain data up to the point Python was terminated.