status bar 补充更改

　1：statusBar字体为白色　　在plist里面设置View controller-based status bar appearance 为 <a target=_blank target="_blank" href="https://www.baidu.com/s?wd=NO&tn=44039180_cpr&fenlei=mv6quAkxTZn0IZRqIHckPjm4nH00T1YLuW-buWn1nWT4uW-Bnjfk0ZwV5Hcvrjm3rH6sPfKWUMw85HfYnjn4nH6sgvPsT6KdThsqpZwYTjCEQLGCpyw9Uz4Bmy-bIi4WUvYETgN-TLwGUv3EnHbYP1D1n1fdPHn3nWTzPjfvr0" class="baidu-highlight" rel="nofollow" style="text-decoration: none; color: rgb(45, 100, 179);">NO</a>；设置statusBarStyle 为 UIStatusBarStyleLightContent　　2:设置statusBar和navigationbar为一体　　　　[nav.navigationBar setBackgroundImage:[UIImage imageNamed:@"bg_navbar.png"] forBarPosition:UIBarPositionTopAttached barMetrics:UIBarMetricsDefault];　　　　　　3：tabBarItem被选中没效果，需要调用sdk7中的方法：　　　　//兼容ios7以前　　[viewController.tabBarItem setFinishedSelectedImage:actionMenu.selectedIcon withFinishedUnselectedImage:actionMenu.icon];　　//ios7的方法　　viewController.tabBarItem.selectedImage = actionMenu.selectedIcon;　　　　4：刷新状态栏statusBar　　　　[self setNeedsStatusBarAppearanceUpdate]　　5：navigationbar上面的BarButtonItem字看不见问题，backBarItem箭头没有，则需要　　　　//ios7设置BarButtonItem字体颜色，则会显示出来，不包括返回箭头　　[[UIBarButtonItem appearance] setBackButtonTitlePositionAdjustment:UIOffsetMake(0, 0) forBarMetrics:UIBarMetricsDefault];　　//设置BarButtonItem颜色，包括返回箭头　　[[UINavigationBar appearance] setTintColor:[UIColor whiteColor]];　　　　6:取消ios7自带手势，比如navigationcontroller的右滑返回　　　　self.navigationController.interactivePopGestureRecognizer.enabled = <a target=_blank target="_blank" href="https://www.baidu.com/s?wd=NO&tn=44039180_cpr&fenlei=mv6quAkxTZn0IZRqIHckPjm4nH00T1YLuW-buWn1nWT4uW-Bnjfk0ZwV5Hcvrjm3rH6sPfKWUMw85HfYnjn4nH6sgvPsT6KdThsqpZwYTjCEQLGCpyw9Uz4Bmy-bIi4WUvYETgN-TLwGUv3EnHbYP1D1n1fdPHn3nWTzPjfvr0" class="baidu-highlight" rel="nofollow" style="text-decoration: none; color: rgb(45, 100, 179);">NO</a> ;