Bug XXX, go-out current mark in tabs bar on changing tabs' enable/disable on settings

- bugfix, go-out current mark in tabs bar on changing tabs' enable/disable on settings

- TODO: check item.title is current
I think it use enum like `UIBarButtonSystemItem`

e.g.
```
enum ToolbarPanelItem : Int {

    case Tabs
    case Bookmarks
    case History
    case Reader
    case Settings

    func toString() -> String {
        switch self {
        case Tabs:
            return "Tabs"
        case Bookmarks:
            return "Bookmarks"
        case History:
            return "History"
        case Reader:
            return "Reader"
        case Settings:
            return "Settings"
        }
    }
}
```