★ UITabBarItemに画像を設定する
let itemImage = UIImage(named: "image")?.imageWithRenderingMode(UIImageRenderingMode.AlwaysOriginal)
let item = UITabBarItem(title: "item", itemImage: image, tag: 1)★ バッジを付ける(String)
item.badgeValue = "1"★ SystemItemを設定する
let item = UITabBarItem(tabBarSystemItem: .Contacts, tag: 1)
/*
UITabBarSystemItem
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*/