date: format all returned dates as string.

1) Add _formatRetDate() to format date to string.
2) Formated all returned dates to strings.

Signed-off-by: Zhengwang Ruan <ruan.zhengwang@gmail.com>
dataMgr:importer: sync in wr

sync in wr.

Signed-off-by: Zhengwang Ruan <ruan.zhengwang@gmail.com>