fix(peer_server): graceful stop for peer server run

Peer server will be started and stopped repeatedly in the design.
This step ensures its stop doesn't affect the next start.
The patch includes goroutine stop and timer trigger remove.
chore(server): rename daemon to startRoutine

For better understanding.
Merge pull request #675 from unihorn/56

fix(peer_server): exit all server goroutines in Stop()