Overview:   [VC] Add -i command

Platform:   offline
Modlue:     VeryCD Mirror
Description:-i command, the first following parameter is start id, the second is
            step. 10 theads in all are used to get the data.
TODO:
            1.Check each 10 threads insert result. Reinsert for the missed ones
            2.Get input the range of items
            3.Topic support.
            4.Command support.