Feature: Updated README

Updated README from Dhruv Bansal

Squashed commit of the following:

commit a25383bbb6d1cf800f5d65a803c2e69ada6496b7
Author: Dhruv Bansal <dhruv@ph.utexas.edu>
Date:   Fri Mar 21 14:27:09 2014 -0500

    updated README with more context for reading from ElasticSearch

commit e24104f608be78bdf5f4e0241141747b83537af6
Author: Dhruv Bansal <dhruv@ph.utexas.edu>
Date:   Fri Mar 21 10:56:13 2014 -0500

    updated README to be more accurate based on all the work we've done recently

commit c069fbfe079b3451cf6781102b4f4f731a0a20fe
Author: David Snyder <david@infochimps.com>
Date:   Wed Mar 19 16:27:50 2014 -0500

    Bump wukong-hadoop to 0.2.0, fix deprecation warnings

    Change-Id: I61161789c66aa92ddd57674a97affa354964aef3

Change-Id: Ie467be7a4b720338e144eba065bcf7741878eb1a