title: Error while compiling cocos2d-x v3 IOS project,on integrating AdMob (IOS) framework
body: <p>When i compile my cocos2d-x V3 project in Xcode, it runs fine but on including AdMob framework, it displays following linker error.</p>
  
  <p>I already have included "-ObjC" in "Other linker" section under Build Settings.</p>
  
  <blockquote>
    <p>Undefined symbols for architecture armv7:
      "_kCMTimeZero", referenced from:
          -[GADVideoPlayer setAudioMixVolume:] in GoogleMobileAds(GADVideoPlayer.o)
      "_CMTimeMakeWithSeconds", referenced from:
          -[GADVideoPlayer seekToTime:] in GoogleMobileAds(GADVideoPlayer.o)
      "_CMTimeGetSeconds", referenced from:
          -[GADVideoPlayer notifyVideoPlayerWithTime:] in GoogleMobileAds(GADVideoPlayer.o)
          -[GADVideoPlayer notifyVideoReadyToPlay] in GoogleMobileAds(GADVideoPlayer.o)
      "_CMTimeMake", referenced from:
          -[GADVideoPlayer observePlayer] in GoogleMobileAds(GADVideoPlayer.o)
      "_OBJC_CLASS_$_EKEventEditViewController", referenced from:
          objc-class-ref in GoogleMobileAds(GADOpener.o)
      "_OBJC_CLASS_$_MFMailComposeViewController", referenced from:
          objc-class-ref in GoogleMobileAds(GADOpener.o)
      "_SCNetworkReachabilityCreateWithAddress", referenced from:
          l001 in GoogleMobileAds(GADGestureUtil.o)
      "_OBJC_CLASS_$_MFMessageComposeViewController", referenced from:
          objc-class-ref in GoogleMobileAds(GADDevice.o)
          objc-class-ref in GoogleMobileAds(GADOpener.o)
      "_SCNetworkReachabilitySetCallback", referenced from:
          ___35-[GADNetwork enableNetworkChecking]_block_invoke in GoogleMobileAds(GADNetwork.o)
      "_SCNetworkReachabilityGetFlags", referenced from:
          l001 in GoogleMobileAds(GADGestureUtil.o)
      "_OBJC_CLASS_$_EKEventStore", referenced from:
          objc-class-ref in GoogleMobileAds(GADSlot+MRAID.o)
          objc-class-ref in GoogleMobileAds(GADOpener.o)
      "_SCNetworkReachabilitySetDispatchQueue", referenced from:
          ___35-[GADNetwork enableNetworkChecking]_block_invoke in GoogleMobileAds(GADNetwork.o)
          ___36-[GADNetwork disableNetworkChecking]_block_invoke in GoogleMobileAds(GADNetwork.o)
      "_OBJC_CLASS_$_EKEvent", referenced from:
          objc-class-ref in GoogleMobileAds(GADOpener.o)
      "_OBJC_CLASS_$_ASIdentifierManager", referenced from:
          objc-class-ref in GoogleMobileAds(GADDevice.o)
          objc-class-ref in GoogleMobileAds(GADInAppPurchaseTransactionReporter.o)
          objc-class-ref in GoogleMobileAds(GADGestureIdUtil.o)
          objc-class-ref in GoogleMobileAds(GADMAdURLAdapter.o)
      "_SCNetworkReachabilityCreateWithName", referenced from:
          ___35-[GADNetwork enableNetworkChecking]_block_invoke in GoogleMobileAds(GADNetwork.o)
      "_OBJC_CLASS_$_CTTelephonyNetworkInfo", referenced from:
          objc-class-ref in GoogleMobileAds(GADDevice.o)
      "_CTRadioAccessTechnologyDidChangeNotification", referenced from:
          ___48-[GADDevice enableRadioAccessTechnologyChecking]_block_invoke_2 in GoogleMobileAds(GADDevice.o)
    ld: symbol(s) not found for architecture armv7
    clang: error: linker command failed with exit code 1 (use -v to see invocation)</p>
  </blockquote>