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
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
refactor(peer.go) clean up debugging info
Merge pull request #136 from goraft/refactor

Refactor
test(server_test.go) Fix a deadlock.
We stop all the servers before finishing the MultiNode test. The mock transporter directly calls to the function of the target server. If the target is stopped, the transporter will just hang there waiting for a reply. So the sender server will also hang for a reply. We add a timeout for the reply to solve this problem.
Fix spelling mistake in snapshot.go comment
Merge pull request #149 from xiangli-cmu/spelling_fix

Fix spelling mistake in snapshot.go comment
Merge branch 'master' of https://github.com/goraft/raft