title: error: 'create' is not a member of 'cv::Tracker'
body: <p>İn <a href="http://docs.opencv.org/3.1.0/d2/d0a/tutorial_introduction_to_tracker.html" rel="noreferrer">this</a> official tutorial I got the error in title. What should be the reason?</p>
  
  <pre><code>Ptr&lt;Tracker&gt; tracker = Tracker::create( "KCF" );
  </code></pre>
  
  <p>Here the part of tracking.hpp:</p>
  
  <pre><code>    @endcode
      of course, you can also add any additional methods of your choice. It should be pointed out,
      however, that it is not expected to have a constructor declared, as creation should be done via
      the corresponding createTracker() method.
     In src/tracker.cpp file add BOILERPLATE_CODE(name,classname) line to the body of
      Tracker::create() method you will find there, like :
  @code
          Ptr&lt;Tracker&gt; Tracker::create( const String&amp; trackerType )
          {
            BOILERPLATE_CODE("BOOSTING",TrackerBoosting);
            BOILERPLATE_CODE("MIL",TrackerMIL);
            return Ptr&lt;Tracker&gt;();
          }
  @endcode
  -   Finally, you should implement the function with signature :
  @code
          Ptr&lt;classname&gt; classname::createTracker(const classname::Params &amp;parameters){
              ...
          }
  @endcode
  </code></pre>
  
  <p>I am using 3.2.0 release.  </p>