Ready: Add Java to Data Types modeling doc

@broach Ready for review
Make these Javadocs:

```java
	/**
	 * While we're at it, we'll create a couple of private helper
	 * methods that will assist us later in the tutorial. This method
	 * fetches our map's abstract context object, which assists
	 * Riak in making intelligent decisions behind the scenes about
	 * map convergence:
	 */
```