Updated Spark SQL README to include the hive-thriftserver module

Author: Reynold Xin <rxin@apache.org>

Closes #1867 from rxin/sql-readme and squashes the following commits:

42a5307 [Reynold Xin] Updated Spark SQL README to include the hive-thriftserver module

sql/README.md

@@ -3,10 +3,11 @@ Spark SQL
 
 This module provides support for executing relational queries expressed in either SQL or a LINQ-like Scala DSL.
 
-Spark SQL is broken up into three subprojects:
+Spark SQL is broken up into four subprojects:
  - Catalyst (sql/catalyst) - An implementation-agnostic framework for manipulating trees of relational operators and expressions.
  - Execution (sql/core) - A query planner / execution engine for translating Catalyst’s logical query plans into Spark RDDs.  This component also includes a new public interface, SQLContext, that allows users to execute SQL or LINQ statements against existing RDDs and Parquet files.
  - Hive Support (sql/hive) - Includes an extension of SQLContext called HiveContext that allows users to write queries using a subset of HiveQL and access data from a Hive Metastore using Hive SerDes.  There are also wrappers that allows users to run queries that include Hive UDFs, UDAFs, and UDTFs.
+ - HiveServer and CLI support (sql/hive-thriftserver) - Includes support for the SQL CLI (bin/spark-sql) and a HiveServer2 (for JDBC/ODBC) compatible server.
 
 
 Other dependencies for developers