SPARK-2481: The environment variables SPARK_HISTORY_OPTS is covered in spark-env.sh

Author: witgo <witgo@qq.com>
Author: GuoQiang Li <witgo@qq.com>

Closes #1341 from witgo/history_env and squashes the following commits:

b4fd9f8 [GuoQiang Li] review commit
0ebe401 [witgo] *-history-server.sh load spark-config.sh

sbin/start-history-server.sh

@@ -27,6 +27,9 @@
 sbin=`dirname "$0"`
 sbin=`cd "$sbin"; pwd`
 
+. "$sbin/spark-config.sh"
+. "$SPARK_PREFIX/bin/load-spark-env.sh"
+
 if [ $# != 0 ]; then
   echo "Using command line arguments for setting the log directory is deprecated. Please "
   echo "set the spark.history.fs.logDirectory configuration option instead."