[7/7] spark git commit: [SPARK-6943] [SPARK-6944] DAG visualization on SparkUI

[SPARK-6943] [SPARK-6944] DAG visualization on SparkUI This patch adds the functionality to display the RDD DAG on the SparkUI. This DAG describes the relationships between - an RDD and its dependencies, - an RDD and its operation scopes, and - an RDD's operation scopes and the stage / job

[7/7] spark git commit: [SPARK-6943] [SPARK-6944] DAG visualization on SparkUI

[SPARK-6943] [SPARK-6944] DAG visualization on SparkUI This patch adds the functionality to display the RDD DAG on the SparkUI. This DAG describes the relationships between - an RDD and its dependencies, - an RDD and its operation scopes, and - an RDD's operation scopes and the stage / job