[iOS8] Push Notification 변경사항.

기존에 잘 쓰고있던 프로젝트에서 iOS8 업데이트 이후에 푸쉬키를 못얻어오는 현상이 발생하여 확인하여보니 

약간의 변경이 있었던것 같습니다.

// Before iOS 8:

[[UIApplication sharedApplication] registerForRemoteNotificationTypes:UIRemoteNotificationTypeAlert |

                                                                      UIRemoteNotificationTypeBadge |

                                                                      UIRemoteNotificationTypeSound];

// For iOS 8:

UIUserNotificationSettings *settings =

    [UIUserNotificationSettings settingsForTypes:UIUserNotificationTypeAlert |

                                                 UIUserNotificationTypeBadge |

                                                 UIUserNotificationTypeSound

                                      categories:nil];

[[UIApplication sharedApplication] registerUserNotificationSettings:settings];

[[UIApplication sharedApplication] registerForRemoteNotifications];

iOS 버전별 분기를 통하여 처리해주시면 될것 같습니다.