GEOMESA-215 GeoMesa query should be exclusive of temporal filter date bo...

...unds 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.
I suspect there will be some push-back on the type declaration here.