[GH-359] Hydrator hotfix - parent object association

This issue is created automatically through a Github pull request on behalf of splitin2:

Url: https://github.com/doctrine/doctrine2/pull/359

Message:

Found that using a mixed sql and more than 2 entities the hydrator skips one related association and inserts the third related entity wrongly.

In the case below "c" will be inserted into "a"

<code>SELECT SUM(a.sold) as total, a, b, c FROM Entity\A a LEFT JOIN a.test1 b LEFT JOIN b.test2 c GROUP BY a.id</code>

On a later flush call this will result in ORM\Exception
<pre>
Found entity of type Entity\A on association Entity\C#test2, but expecting Entity\B
</pre>