SPARK-1136: Fix FaultToleranceTest for Docker 0.8.1

This patch allows the FaultToleranceTest to work in newer versions of Docker.
See https://spark-project.atlassian.net/browse/SPARK-1136 for more details.

Besides changing the Docker and FaultToleranceTest internals, this patch also
changes the behavior of Master to accept new Workers which share an address
with a Worker that we are currently trying to recover. This can only happen
when the Worker itself was restarted and got the same IP address/port at the
same time as a Master recovery occurs.

Finally, this adds a good bit of ASCII art to the test to make failures,
successes, and actions more apparent. This is very much needed.