Meta-Issue: Error reporting and logging

[dannylamb]

This is a meta issue to track developments w/r/t error reporting and logging. Please refer to this issue in any subsequent issues to link them.

Islandora CLAW, by nature, is distributed and asynchronous. This leads to lots of improvements in scalability, but adds a layer of difficulty to debugging when things go awry. There's a lot of logs to check with no real feedback to the user other than they're not receiving the behaviour they're expecting. Additionally, all those logs will be on separate boxes as the system scales, making it even more onerous to diagnose issues. There's lots of room for improvement in developer and sysadmin experience, and perhaps we could even consider taking on a solution such as ELK to make things better.