[SPARK-2590][SQL] Added option to handle incremental collection, disabled by default

JIRA issue: [SPARK-2590](https://issues.apache.org/jira/browse/SPARK-2590)
Lets put this under `spark.sql.thriftServer...`.  Also, what do you think about putting it in with the thrift server instead?  It seems kinda odd to me to be configuring things for the thrift server in a place where the code doesn't even exist.  This is how we do things for Hive now (see `HiveContext` in #1819 ).