[SPARK-7907] [SQL] [UI] Rename tab ThriftServer to SQL.

This PR has three changes:
1. Renaming the table of `ThriftServer` to `SQL`;
2. Renaming the title of the tab from `ThriftServer` to `JDBC/ODBC Server`; and
3. Renaming the title of the session page from `ThriftServer` to `JDBC/ODBC Session`.

https://issues.apache.org/jira/browse/SPARK-7907

Author: Yin Huai <yhuai@databricks.com>

Closes #6448 from yhuai/JDBCServer and squashes the following commits:

eadcc3d [Yin Huai] Update test.
9168005 [Yin Huai] Use SQL as the tab name.
221831e [Yin Huai] Rename ThriftServer to JDBCServer.

sql/hive-thriftserver/src/main/scala/org/apache/spark/sql/hive/thriftserver/ui/ThriftServerPage.scala

@@ -47,7 +47,7 @@ private[ui] class ThriftServerPage(parent: ThriftServerTab) extends WebUIPage(""
       </h4> ++
       generateSessionStatsTable() ++
       generateSQLStatsTable()
-    UIUtils.headerSparkPage("ThriftServer", content, parent, Some(5000))
+    UIUtils.headerSparkPage("JDBC/ODBC Server", content, parent, Some(5000))
   }
 
   /** Generate basic stats of the thrift server program */
@@ -143,7 +143,7 @@ private[ui] class ThriftServerPage(parent: ThriftServerTab) extends WebUIPage(""
       val headerRow = Seq("User", "IP", "Session ID", "Start Time", "Finish Time", "Duration",
         "Total Execute")
       def generateDataRow(session: SessionInfo): Seq[Node] = {
-        val sessionLink = "%s/ThriftServer/session?id=%s"
+        val sessionLink = "%s/sql/session?id=%s"
           .format(UIUtils.prependBaseUri(parent.basePath), session.sessionId)
         <tr>
           <td> {session.userName} </td>

sql/hive-thriftserver/src/main/scala/org/apache/spark/sql/hive/thriftserver/ui/ThriftServerSessionPage.scala

@@ -55,7 +55,7 @@ private[ui] class ThriftServerSessionPage(parent: ThriftServerTab)
         Total run {sessionStat._2.totalExecution} SQL
       </h4> ++
       generateSQLStatsTable(sessionStat._2.sessionId)
-    UIUtils.headerSparkPage("ThriftServer", content, parent, Some(5000))
+    UIUtils.headerSparkPage("JDBC/ODBC Session", content, parent, Some(5000))
   }
 
   /** Generate basic stats of the streaming program */

sql/hive-thriftserver/src/main/scala/org/apache/spark/sql/hive/thriftserver/ui/ThriftServerTab.scala

@@ -27,7 +27,9 @@ import org.apache.spark.{SparkContext, Logging, SparkException}
  * This assumes the given SparkContext has enabled its SparkUI.
  */
 private[thriftserver] class ThriftServerTab(sparkContext: SparkContext)
-  extends SparkUITab(getSparkUI(sparkContext), "ThriftServer") with Logging {
+  extends SparkUITab(getSparkUI(sparkContext), "sql") with Logging {
+
+  override val name = "SQL"
 
   val parent = getSparkUI(sparkContext)
   val listener = HiveThriftServer2.listener

sql/hive-thriftserver/src/test/scala/org/apache/spark/sql/hive/thriftserver/UISeleniumSuite.scala

@@ -84,11 +84,11 @@ class UISeleniumSuite
 
       eventually(timeout(10 seconds), interval(50 milliseconds)) {
         go to baseURL
-        find(cssSelector("""ul li a[href*="ThriftServer"]""")) should not be None
+        find(cssSelector("""ul li a[href*="sql"]""")) should not be None
       }
 
       eventually(timeout(10 seconds), interval(50 milliseconds)) {
-        go to (baseURL + "/ThriftServer")
+        go to (baseURL + "/sql")
         find(id("sessionstat")) should not be None
         find(id("sqlstat")) should not be None