title: NSString formatting
body: <p>I'm changing some pre-written code and a video timeLabel is formatted like so:</p>
  
  <pre><code>return [NSString stringWithFormat:@"%2d:%0.2d", minutes, seconds];
  </code></pre>
  
  <p>What's happening is the if the <code>minutes</code> is a single digit, it's returning a space before it, eg <code>4:49</code> has a space before the 4. How do I format so that there are 2 characters in the string if the <code>minutes</code> arguments is 2 digits, but just 1 character if <code>minutes</code> is 1 digit?</p>