Added logging for serialization / deserialization.

Serialization when data is read/written using Hadoop is not
captured.
Change to ec2 script to pull in TPC-DS stuff
Read /proc filesystem to log CPU/Network/Disk utilization.

Logging can be enabled by setting the spark.procParser.enabled
configuration variable, and the logging interval can be configured
with spark.procParser.logIntervalMillis.
Don't do proc parsing on master