title: Problems running OAuthSwift
body: <p>I am using OAuthSwift and whenever I run this function</p>
  
  <pre><code>func doOAuthTwitter(){
      let oauthswift = OAuth1Swift(
          consumerKey:   "...",
          consumerSecret: "...",
          requestTokenUrl: "https://api.twitter.com/oauth/request_token",
          authorizeUrl:    "https://api.twitter.com/oauth/authorize",
          accessTokenUrl:  "https://api.twitter.com/oauth/access_token"
      )
      oauthswift.authorize_url_handler = WebViewController()
      oauthswift.authorizeWithCallbackURL( NSURL(string: "oauth-swift://oauth-callback/twitter")!, success: {
          credential, response in
          self.showAlertView("Twitter", message: "auth_token:\(credential.oauth_token)\n\noauth_toke_secret:\(credential.oauth_token_secret)")
          var parameters =  Dictionary&lt;String, AnyObject&gt;()
          oauthswift.client.get("https://api.twitter.com/1.1/statuses/home_timeline.json", parameters: parameters,
              success: {
                  data, response in
                  let jsonDict: AnyObject! = NSJSONSerialization.JSONObjectWithData(data, options: nil, error: nil)
                  println(jsonDict)
              }, failure: {(error:NSError!) -&gt; Void in
                  println(error)
          })
          }, failure: {(error:NSError!) -&gt; Void in
              println(error.localizedDescription)
          }
      )
  }
  </code></pre>
  
  <p>the function seems to run until after this point</p>
  
  <pre><code>oauthswift.authorize_url_handler = WebViewController()
  </code></pre>
  
  <p>authorizeWithCallbackURL doesn't even start and the jsonDict does not print. I've tried my access codes through the OAuthSwift demo, and it works fine with the tableView, printing out the JsonDict. I have no idea why authorizeWithCallbackURL goes completely ignored when I use it outside of the demo.</p>