add fast sync func (#204)
* Modify fast sync function
* Fix GetHeadersMessage error
* Fix skeleton init error
* Fix fetchHeaders error
* Add fetch date finish check
* Fix FetchBodiesTask error
* Fix fetchBodies bug
* Add multi-peer fetch support
* Fix requireHeaders bug
* add lit fast sync func
* Fix fetchBlocks bug
* opz code format
* del test file
* opz code
* Add test case
* change to singe peer fast sync
* Fix bug
* Add peer exception handle
* del unused code
* Add test case
* Fix review bug
* Fix locate headers error
* Fix test file error
* Add irreversible block fast sync
* Fix test err
* Fix review bug
- [D] netsync/chainmgr/protocol_reactor.go