title: iOS backwards compatibility issue in Xcode
body: <p>I'm developing with Xcode 4.6.2, which includes iOS 6.1 SDK. I need to make my app compatible from iOS 5, and I don`t know exactly how should I manage this backwards compatibility. I've downloaded the iOS 5.0 simulator, but I'm not sure if I also need to get the iOS 5.0 SDK package, which I don´t know in what Xcode version it is included. I've set de deployment target to 5.0 as well. Does Xcode alert if I try to use in code features that are only available in later iOS versions? Should I try to only use features available in iOS 5.0, or the best practice is to check the device's current iOS version and decide if it can take advantage of newest features if iOS version is later than iOS 5.0?</p>
  
  <p>Thanks in advance</p>