GEOMESA-337 - Speed up writeFeature

* Refactored the Formatters to take the information they might use.
* Additionally, Formatters produce Text at the last moment.
* Simplified a CRS lookup to assume 4326.
GEOMESA-318 Export to STDOUT not working for GML, GeoJSON

* Fixed issue with correct output stream not being assigned when exporting.
* turning collectStats off
* changing logger statements
GEOMESA-160 DWithin for non-point geometries

* Removes assumption that DWithin geometry is a Point.
* Adds tests to show that the filter is working as we expect the rewrite to.

Randy Attai submitted the original fix.  I cooked up the uni tests.
GEOMESA-327 fixing Try around hadoop initialization
GEOMESA-336 - Clean up dependency management
GEOMESA-93 Implement KNN as a WPS function

* Add a K-Nearest Neighbors Search that implements a GeoHash-by-GeoHash query strategy.
* Expose the KNN Search as a WPS process.
* Include an example KNN Search based on the location of the White House.
* Add a bounded PriorityQueue implementation.
* Add a method which, given a GeoHash, retrieves a list of all other GeoHashes in contact with it.
* Using the above method, implement a 'GeoHashSpiral' an Iterator that produces GeoHashes in order of distance from a point.
GEOMESA 325: allow ingest without date information
* date information flags like dtformat and dtfield are now optional.
* added tests to check that writing the features worked.
* updated readme.
* addressed comments on pr
* Added fix to issue noted in GEOMESA-338
* Fixed issue with SVIngest tests failing, minor refactoring of datetime builder
* switched to using commons-csv to parse file
WIP - Release 1.0 tarball

Running with mvn package -P assemble now generates a tarball under geomesa-assemble/target. Further instructions
are found in the GeoMesa tools README.
use our own license
updates to README
small changes to make bundling the tarball better and easier
adding ability to override instanceName and zookeepers
changing to HADOOP_CONF_DIR and updating accumulo dependency to be provided
splitting export up in geomesa-tools and updating pom
no longer including shaded jars, including dependencies, adding debug option to geomesa shell wrapper
removing unnecessary env variable