title: SQL Join in ZF3 Expressive - ResultSet does not give joined Columns
body: <p>I'm trying to get a title out of a second table (by left-join) but my resultSet isn't delivering the column of the joined table.</p>
  
  <p>This is how my TableGateway looks like:</p>
  
  <pre><code> public function fetchCourseListWithStudyprogram()
  {
          $select = $this-&gt;getSql()-&gt;select();
          $select-&gt;where-&gt;equalTo('course_active', 'Y');
          $select-&gt;join('studyprogram', 'studyprogram.studyprogram_id = course.studyprogram_id', ['studyprogram_title'], $select::JOIN_LEFT);
  
      $resultSet = $this-&gt;selectWith($select);
      var_dump($resultSet);
      return $resultSet-&gt;toArray();
  }
  </code></pre>
  
  <p>The statement is getting constructed as it should be:</p>
  
  <pre><code>public 'queryString' =&gt; string 'SELECT `course`.*, `studyprogram`.`studyprogram_title` AS `studyprogram_title` FROM `course` LEFT JOIN `studyprogram` ON `studyprogram`.`studyprogram_id` = `course`.`studyprogram_id` WHERE `course_active` = :where1' (length=214)
  </code></pre>
  
  <p>When it comes to getting results, it ignores the "studyprogram_title" column, I guess its because of the given resultSet (with binded CourseEntity)</p>
  
  <p>Is there any way to show the studyprogram_title without adding it to the CourseEntity? Its not really a part of it so I guess its dirty if I add it there.</p>