Shell script for creating AMI's.

This installs all the necessary packages and configuration starting with an
Amazon AMI. Tested with Amazon Linux AMI 2014.03.2.
Yeah, I guess its better to make it explicit. Another thing to consider is to see if we can use a different http server like thttpd or lighthttpd. The default httpd has a lot of config options and if the version changes in the AMI it leads to bugs like https://issues.apache.org/jira/browse/SPARK-2649