Update spark-ec2 scripts for 1.0.0 on master

The change was previously committed only to branch-1.0 as part of https://github.com/apache/spark/commit/a34e6fda1d6fb8e769c21db70845f1a6dde968d8

Author: Aaron Davidson <aaron@databricks.com>

This patch had conflicts when merged, resolved by
Committer: Patrick Wendell <pwendell@gmail.com>

Closes #938 from aarondav/sparkec2 and squashes the following commits:

067cc31 [Aaron Davidson] Update spark-ec2 scripts for 1.0.0 on master
SPARK-1806 (addendum) Use non-deprecated methods in Mesos 0.18

The update to Mesos 0.18 caused some deprecation warnings in the build. The change to the non-deprecated version is straightforward as it emulates what the Mesos driver does with the deprecated method anyway (https://github.com/apache/mesos/blob/c5aa1dd22155d79c5a7c33076319299a40fd63b3/src/sched/sched.cpp#L1354)

Author: Sean Owen <sowen@cloudera.com>

Closes #920 from srowen/SPARK-1806 and squashes the following commits:

8d76b6a [Sean Owen] Use non-deprecated methods in Mesos 0.18