GEOMESA-170 - Two query corner cases

* Addressed degenerate intersections in the Geometry utils.
* Properly handles intervals in FilterToAccumulo.
GEOMESA-172 adding try around decoding simple features
GEOMESA-139 Remove inconsistent naming of temporal and geometry attributes in index

Standardize on using geom/dtg for index attributes:
geomesa_index_geometry   --> geom
geomesa_index_start_time --> dtg
and
geomesa_index_end_time   --> dtg_end_time

Reviewed by @anthonyccri
Merge branch 'accumulo1.5.x/1.x' of github.com:locationtech/geomesa into f_set_default_dtg
GEOMESA-144,GEOMESA-140

GEOMESA-140 Warn users about missing temporal component of index
This commit adds a warning when a user neglects to properly set SF_PROPERTY_START_TIME in the UserData. Such a mistake is non-fatal, but does impact performance.

GEOMESA-144 Set temporal index variable by default if not selected by user
This commit will set SF_PROPERTY_START_TIME for the user if a time attribute is present in the SimpleFeatureType, and emit a notification to this effect.