Swift 1.2 function to flush shared cookies

WebView.swift

    public func flushCookies() {
        let storage = NSHTTPCookieStorage.sharedHTTPCookieStorage()
        if let cookieJar = storage.cookies as? [NSHTTPCookie] {
            for cookie in cookieJar { storage.deleteCookie(cookie) }
        }
        NSUserDefaults.standardUserDefaults().synchronize()
    }