refactor(server.go) make async really async.
refactor(peer.go) use async send if possible
refactor(server.go) do not construct the string if not necessary
fix(server.go/peer.go) server.stop should stop heartbeat before close the log
chrod more clear debug info for committing
refactor make deny vote more clear
Merge pull request #143 from goraft/fix_race

fix(server.go)
Add election threshold and heartbeat timeout events.
Merge branch 'master' of https://github.com/goraft/raft
Merge branch 'master' of https://github.com/goraft/raft
Merge pull request #144 from goraft/election-heartbeat-events

Election Threshold and Heartbeat Timeout Event Types
Merge branch 'master' of https://github.com/goraft/raft
remove command timeout
Make HttpTranporter.Transport into an exported field

With this patch, it becomes possible to use the HTTPTransporter over
custom transports, such as Unix sockets.
Merge pull request #146 from gdb/master

Make HttpTranporter.Transport into an exported field
Merge pull request #145 from goraft/remove_timeout

remove command timeout
Fix spelling errors in comments and strings.
Merge pull request #147 from jbcrail/spelling-fixes

Fix spelling errors in comments and strings.
merge with master
refactor(server.go) try non-blocking send first