Moved hiveOperators.scala to the right package folder

The package is `org.apache.spark.sql.hive.execution`, while the file was placed under `sql/hive/src/main/scala/org/apache/spark/sql/hive/`.

Author: Cheng Lian <lian.cs.zju@gmail.com>

Closes #1029 from liancheng/moveHiveOperators and squashes the following commits:

d632eb8 [Cheng Lian] Moved hiveOperators.scala to the right package folder

(cherry picked from commit a9a461c594fd20e46947e318095df60bddb67559)
Signed-off-by: Michael Armbrust <michael@databricks.com>