Fix drop table bug with non-exist tables; fix file split kvs insert error; fix file re-replicate failed bug; print more cmds for DM.
Add list file by digest to manage large scale created files; Investigate the latency/concurrent problem of metastore.
fix the linger file deletion bug: delete the file if there are none valid file locations.
delete some properties about schema
Merge remote-tracking branch 'origin/v0.2' into zhuqihan