mesos/spark — pull request #725 by karenfeng (2013-07-23 20:38:25+00:00)
Title: Creates task start events

This should be the final step to solving [SPARK-808](https://spark-project.atlassian.net/browse/SPARK-808) by creating a column for number of active tasks per executor.
- Creates task start events
- Creates column on Executors UI