Merge pull request #3 from shivaram/master

Remove cluster url as we print this from spark_ec2
Merge pull request #4 from shivaram/master

Set spark mem using slave memory
Small fix to Spark config
Configure JAVA_HOME and SCALA_HOME from environment
Include URI scheme in Mesos cluster_url
Munge cluster_url into format understood by Mesos
Merge pull request #5 from jey/master

Changes for 0.7.2 release
Merge branch 'master' of git://github.com/mesos/spark-ec2

Conflicts:
	templates/root/ephemeral-hdfs/conf/hadoop-env.sh
	templates/root/persistent-hdfs/conf/hadoop-env.sh
	templates/root/spark-ec2/mesos/hadoop-framework-conf/hadoop-env.sh