[SPARK-7566][SQL] Add type to HiveContext.analyzer

This makes HiveContext.analyzer overrideable.

Author: Santiago M. Mola <santi@mola.io>

Closes #6086 from smola/patch-3 and squashes the following commits:

8ece136 [Santiago M. Mola] [SPARK-7566][SQL] Add type to HiveContext.analyzer

sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveContext.scala

@@ -335,7 +335,7 @@ class HiveContext(sc: SparkContext) extends SQLContext(sc) {
 
   /* An analyzer that uses the Hive metastore. */
   @transient
-  override protected[sql] lazy val analyzer =
+  override protected[sql] lazy val analyzer: Analyzer =
     new Analyzer(catalog, functionRegistry, conf) {
       override val extendedResolutionRules =
         catalog.ParquetConversions ::