Fix/expand default TitanGraph config for Hadoop

This commit increases latency tolerance in the default TitanGraph
configuration used by titan-hadoop.  The diff shows exactly which
options are set, but the general idea is to increase timeouts and
retries.  It also sets the buffer-size to Integer.MAX_VALUE to prevent
Titan from chunking a single commit's mutations into multiple
HTable.batch or Cassandra.Client.batch_mutate calls.

This commit also exposed some outdated & hardcoded config option
strings in TitanGraphOutputMapReduce.