GEOMESA-220 Explain does not handle println well
GEOMESA-215 GeoMesa query should be exclusive of temporal filter date bounds for BEGIN, AFTER

* Partitions temporal predicates out and passes them to the STII/AIFI/IndexIterator.
* Adds special handling for DWithin.  (More special cases will be produced as we move away from FilterToAccumulo.)
Thanks to Hunter Provyn for providing the unit tests in FeatureWritersTest.scala.
Accumulo Mini Cluster for local integration testing