add some comments
fix bug in viewservice
detects client time out in viewservice only current view is acked
add debug output
some indent auto fix
Pass basic test
- add Fwd & Sync handler and helper func
  seemed Sync is useless cause i cannot pass map through rpc
- FIXME: temporarily use multiple Fwd to achieve Sync
updateView before return Err when a Non-P receives a Put request
Get return error if not Primary
use Sync RPC to sync state between P and B
- fix bug: db -> DB in SyncArgs
[lab3] define RPC for paxos
- implement simple code for proposer
commit for sync
pass forget mem, partition reminds a problem