Since some of the export tasks have been memory hungry, sometimes killing the executor-services, they've been moved to a separate process that can be given a larger Xmx.
While doing this, the ProcessMainClass was given utilities for the boilerplate surrounding receiving mq requests and responding to them, some effort was also put toward making the process boot process a bit more uniform. It's still a bit heterogeneous between different processes, but a bit less so for now.
Refactoring keyword extraction to extract spans information.
Modifying the intermediate storage of converted data to use the new slop library, which is allows for easier storage of ad-hoc binary data like spans and positions.
This is a bit of a katamari damacy commit that ended up dragging along a bunch of other fairly tangentially related changes that are hard to break out into separate commits after the fact. Will push as-is to get back to being able to do more isolated work.
