GEOMESA-277 Refining DensityIterator Stacking

* Refactored the DensityIterator to be separate from the SFFI.
* Moved the DensityIterator to run after the SFFI.
GEOMESA-282 Change the namespace to org.locationtech.geomesa

Included some import re-ordering.
GEOMESA-201 Compute geometries from Geometry Filters

* This pr makes a first pass at extracting geometries to cover from the geometry filters.
* In order to do this, various things are refactored.
* GeohashUtils.getUniqueGeohashSubstringsInPolygon is widened to accept Geometries.
GEOMESA-226 Compute minimum geodetic distances between two geometries
GEOMESA-270,269,254 Improve ingest in geomesa-tools

* Fixed up csv parser in SVIngest so that quotes are not requried around geometry field, updated readme.
* Added dependency CsvReader for tsv/csv parsing.
* Added back lat/lon field csv/tsv ingest method for adding point data.
* Added tests for SVIngest, test files, refactoring of SVIngest to be better at error catching.
* Added counts for errors, successes and lines to allow for more informative logger messages.
* Added check to not create the schema for the data store if extant.
* Made lineToFeature make the date-time object if abscent from intermediate simplefeature.