Make logging statements slightly more accurate

Due to the lazy evaluation of a Traversable, reprojection does not occur until the next step.
Log memory usage and upgrade to newer geoscript
Don't cache region in memory after ingestion

It uses extra memory.  Regions may not be used immediately afterwards anyway,
the current workflow is that curated regions are ingested ahead of time, and
the point datasets that georegioncode against them are upserted later, and
updates are sent on a regular basis.
Improve memory logging
Add automatic memory depressurization and fail fast logic

- Ingest throws an error if more than 80% of memory used
  during reprojection
- Loading regions to cache will attempt to remove other regions
  in order to free memory
Add a route to list the cached regions
Revert back to geoscript.scala 0.8.3

Don't need 0.8.4 or newer yet, and not ready to release newer version anyways
Make depressurization params configurable
Add target-free-percentage param and fix some stuff
CR from @chitang
Add enable-depressurize config;  make tests pass
Merge pull request #23 from socrata/velvia/improve-oom-crashes

Much improved memory management and failure handling