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' into ah-2ndaryindex

Conflicts:
	geomesa-core/src/main/scala/geomesa/core/data/AccumuloDataStore.scala
	geomesa-core/src/test/scala/geomesa/core/iterators/SpatioTemporalIntersectingIteratorTest.scala