J unit doc tests

Data points for theories

Iterable data points

It's already the case in 4.5 that the DataPoints annotation can identify all elements of an array as valid inputs for theories in the class:

/**
 * 
 */
package org.junit.doc.examples;

import static org.junit.Assert.assertTrue;

import org.junit.experimental.theories.DataPoints;
import org.junit.experimental.theories.Theories;
import org.junit.experimental.theories.Theory;
import org.junit.runner.RunWith;

@RunWith(Theories.class)
public class GreaterThanZeroArray {
	@DataPoints
	public static int[] ints = new int[] { 1, 2, 3 };

	@Theory public void greaterThanZero(int x) {
		assertTrue(x > 0);
	}
}
We'd like to be able to have DataPoints also annotate any Iterable object of the appropriate type:
/**
 * 
 */
package org.junit.doc.examples;

import static org.junit.Assert.assertTrue;

import java.util.Arrays;

import org.junit.experimental.theories.DataPoints;
import org.junit.experimental.theories.Theories;
import org.junit.experimental.theories.Theory;
import org.junit.runner.RunWith;

@RunWith(Theories.class)
public class GreaterThanZeroIterable {
	@DataPoints
	public static Iterable<Integer> ints = Arrays.asList(1, 2, 3);

	@Theory public void greaterThanZero(int x) {
		assertTrue(x > 0);
	}
}