title: Catching NS_AVAILABLE_IOS while coding
body: <p>I know how to change the lowest OS supported with <code>IPHONEOS_DEPLOYMENT_TARGET</code>. I am currently developing under Xcode 4.5 and using the iOS 6.0 SDK.</p>
  
  <p>What I'd like to do is find a way to throw a warning in compilation whenever I use code that is marked:
  NS_AVAILABLE_IOS(6_0)</p>
  
  <p>So that I can make sure that I don't miss any "Yes, but you're on iOS 5 so don't use this code" areas that will crash the user's device.</p>