Fixes to imports; add back requiredChildDistribution (lost when merging)

Author: concretevitamin

sql/core/src/main/scala/org/apache/spark/sql/execution/joins.scala

@@ -170,6 +170,9 @@ case class LeftSemiJoinHash(
 
   val buildSide = BuildRight
 
+  override def requiredChildDistribution =
+    ClusteredDistribution(leftKeys) :: ClusteredDistribution(rightKeys) :: Nil
+
   override def output = left.output
 
   def execute() = {

sql/core/src/main/scala/org/apache/spark/sql/parquet/ParquetRelation.scala

@@ -27,14 +27,10 @@ import parquet.hadoop.ParquetOutputFormat
 import parquet.hadoop.metadata.CompressionCodecName
 import parquet.schema.MessageType
 
-import org.apache.spark.sql.SQLContext
 import org.apache.spark.sql.catalyst.analysis.{MultiInstanceRelation, UnresolvedException}
 import org.apache.spark.sql.catalyst.expressions.Attribute
 import org.apache.spark.sql.catalyst.plans.logical.{LogicalPlan, LeafNode}
 
-// Implicits
-import scala.collection.JavaConversions._
-
 /**
  * Relation that consists of data stored in a Parquet columnar format.
  *