title: NSAttributedString Draws No Stroke with NSStrokeColorAttributeName and NSStrokeWidthAttributeName Set
body: <p>This example below is supposed to draw a stroke together with fill but it does not. What is wrong? I am using negative value to have stoke showed up according to Apple's documentation. If I make it a positive value, then text completely disappears. </p>
  
  <pre><code>UITextView *rte = [[UITextView alloc]initWithFrame:
                                    CGRectMake(50,50,100,100)];
  
  [self.view addSubview:rte];
  NSDictionary *typingAttributes = @{
                                     NSFontAttributeName: [UIFont fontWithName:@"Helvetica-Bold" size:20.0f],
                                     NSForegroundColorAttributeName : [UIColor redColor],
                                     NSStrokeColorAttributeName : [UIColor yellowColor],
                                     NSStrokeWidthAttributeName : [NSNumber numberWithFloat:-2.0]
                                     };
  NSAttributedString *str = [[NSAttributedString alloc]
                             initWithString:@"Enter text here..."
                             attributes:typingAttributes];
  rte.attributedText = str;
  </code></pre>