* Add new P2P protocol NewFile
* Publish NewFile message when any file finalized
* handle NewFile message in router
* handle NewFile in sync servic to write in db
* use propagation source to handle NewFile message
* Disable sequential sync and store new file in v2 sync store
* Add shard config in FindFile
* Add AnnounceFile RPC message in network layer
* do not propagate FindFile to whole network
* Mark peer connected if FileAnnouncement RPC message received
* fix unit test failures
* Change P2P protocol version
* Ignore py tests of sequential auto sync
* Add py test for auto sync v2
* fmt code
* remove dummy code in py test
* fix random test failure
* Add comments
* Enable file sync protocol v2 in config file by default
