Merge pull request #15 from yifan-gu/dev

fix a typo
prepare prototype and a few other fixes
Merge pull request #16 from yifan-gu/dev

change logger message to fmt.Someting, fix a bug in commit and the test....
Merge branch 'dev' of github.com:go-epaxos/epaxos into dev
Merge pull request #18 from yifan-gu/dev

change phase2 testing helper names
Merge branch 'dev' of github.com:go-epaxos/epaxos into dev
Merge pull request #17 from fengjingchao/dev

prepare prototype and a few other fixes
rename prepare to recovery and refactor new instanceinfo
Merge pull request #19 from fengjingchao/dev

rename prepare to recovery and refactor new instanceinfo
finish simple recvPrepare()