title: iOS UIButton with multiple labels
body: <p>I have a UI button that I'd like to put two labels on it, similar to how a cell has a title text and detail text.</p>
  
  <p>I'd like the button to have a larger font for the main text, and have smaller detail text under that.</p>
  
  <p>Is this possible?  I've tried to put multiple lines on a button, but I need to have different text sizes for each line, so setting the lineBreakMode and numberOfLines of the titleLabel doesn't really quite work.</p>