[SPARK-7011] Build(compilation) fails with scala 2.11 option, because…

… a protected[sql] type is accessed in ml package.

[This](https://github.com/apache/spark/blob/master/mllib/src/main/scala/org/apache/spark/ml/feature/VectorAssembler.scala#L58) is where it is used and fails compilations at.

Author: Prashant Sharma <prashant.s@imaginea.com>

Closes apache#5593 from ScrapCodes/SPARK-7011/build-fix and squashes the following commits:

e6d57a3 [Prashant Sharma] [SPARK-7011] Build fails with scala 2.11 option, because a protected[sql] type is accessed in ml package.

sql/catalyst/src/main/scala/org/apache/spark/sql/types/dataTypes.scala

@@ -299,7 +299,7 @@ class NullType private() extends DataType {
 case object NullType extends NullType
 
 
-protected[sql] object NativeType {
+protected[spark] object NativeType {
   val all = Seq(
     IntegerType, BooleanType, LongType, DoubleType, FloatType, ShortType, ByteType, StringType)
 
@@ -327,7 +327,7 @@ protected[sql] object PrimitiveType {
   }
 }
 
-protected[sql] abstract class NativeType extends DataType {
+protected[spark] abstract class NativeType extends DataType {
   private[sql] type JvmType
   @transient private[sql] val tag: TypeTag[JvmType]
   private[sql] val ordering: Ordering[JvmType]