Adds Reactive reading of GeoJson
Refactored FeatureCollectionEnumeratee
Adds transaction insert where features are read reactively from the
input stream.

Also moves Reactive JSON support to top-level module.
Better error messages.
Fixes error in updating metadata.
Adds remove transaction API call
Adds the tx/update API POST method.
Adds logging.
Semi-Reactive JSON parser via Jackson.