For debugging and analysis purposes, it's nice to have the exact command
used to launch Spark contained within the logs. This adds the necessary
hooks to make that possible.

Add application metrics to standalone master

Minor clean-up of fair scheduler UI

This adds metrics for applications in the deploy Master.

Enhance job ui in spark ui system with adding pool information

Clean up web UI page headers

Add JSON path to master index page

Conflicts:
	core/src/main/scala/spark/deploy/master/ui/IndexPage.scala

Add data generator for K-means

Conflicts:
	docs/configuration.md

SPARK-842. Maven assembly is including examples libs and dependencies

Bug fix: SPARK-837

Build changes for ML lib

Also made it possible to specify the number of runs in KMeans.main().

Added property 'spark.executor.uri' for launching on Mesos.

Use the Char version of split() instead of the String one in MLUtils

Compression codec change

Refactored Vector.apply(length, initializer) replacing excessive code with library method