add fid and url to filer post result
add fid and url to filer post result

fix https://github.com/chrislusf/seaweedfs/issues/274

k85169336/seaweedfs,chrislusf/seaweedfs,chrislusf/seaweedfs,chrislusf/seaweedfs,hxiaodon/seaweedfs,chrislusf/seaweedfs,k85169336/seaweedfs,hxiaodon/seaweedfs