PHOENIX-933 Local index support to Phoenix

This TODO should be implemented. Just implement a new method on ColumnRef for cloning:

    public ColumnRef cloneAtTimestamp(long timestamp) {
        return new ColumnRef(this, timestamp);
    }

Overide this on LocalIndexDataColumnRef by adding this:

    @Overide
    public LocalIndexDataColumnRef cloneAtTimestamp(long timestamp) {
        return new LocalIndexDataColumnRef(this, timestamp);
    }

Make the ColumnRef(ColumnRef columnRef, long timeStamp) constructor protected and replace existing calls to it with the calls to the new clone method.