title: Swift custom UITableViewCell label is always nil
body: <p>I've been stuck with this problem for days, so I'd be really happy if someone could help.
  I'm trying to create a dynamic UITableView, for which I created a custom UITableView subclass and I've created a custom UITableViewCell subclass as well, because I need several UILabels and a UIButton in each cell.
  The cell is created, but the problem is that the value of the labels is always nil, hence the cell isn't displayed properly.
  <a href="http://prntscr.com/6g91ig" rel="noreferrer">This is</a>, how the storyboard looks like, and <a href="http://prntscr.com/6g924v" rel="noreferrer">this is</a> what I see while running the program.</p>
  
  <p>Here's my UITableViewCell subclass:</p>
  
  <pre><code>import UIKit
  
  class QuestionTableViewCell: UITableViewCell {
  
      @IBOutlet var student: UILabel!
      @IBOutlet var labDesk: UILabel!
      @IBOutlet var topic: UILabel!
      @IBOutlet var answers: UILabel!
  
  }
  </code></pre>
  
  <p>and my UITableView subclass:</p>
  
  <pre><code>import UIKit
  
  class QuestionViewController: UITableViewController, UITableViewDelegate, UITableViewDataSource {
  
      @IBOutlet var table: UITableView!
       struct Question {
          var student: String
          var labDesk: String
          var topic: String
          var answered: String
      }
  
      override func viewDidLoad() {
          super.viewDidLoad()
          table.estimatedRowHeight = 50
          table.dataSource = self
          table.delegate = self
          self.table.registerClass(QuestionTableViewCell.self, forCellReuseIdentifier: "cell")
      }
  
      override func didReceiveMemoryWarning() {
          super.didReceiveMemoryWarning()
      }
  
      override func numberOfSectionsInTableView(tableView: UITableView) -&gt; Int {
          return 1
      }
  
      override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -&gt; Int {
          return 1
      }
  
      override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -&gt; UITableViewCell {
          let cell = tableView.dequeueReusableCellWithIdentifier("cell") as QuestionTableViewCell
          cell.student.text = "random string"
          cell.labDesk?.text = "25/A"
          cell.topic?.text = "string"
          cell.answers?.text = "3"
          return cell
      }
  }
  </code></pre>