Added ability to pull in .ebextensions conf files

Added the ability to pull in eb config and conf files that execute commands on the ec2 instance, as ring ignores any hidden directories by default.  Among other things, this allows you to add gzip compression as described here:
http://www.tonmoygoswami.com/2013/05/how-to-enable-gzip-on-amazon-elastic.html

The basic functions to allow the .ebextensions directory was take from here:
https://github.com/snowplow/snowplow/blob/master/2-collectors/clojure-collector/tasks/leiningen/aws.clj