remove needcmdsinreply and add test for nilstatus preparing handle reply
complete nil status handle prepare reply
finish handle prepare reply at preaccepted recovery
Merge pull request #31 from fengjingchao/inst

remove needcmdsinreply and add test for nilstatus preparing handle reply
add check before increment counts and add test for preaccept ok
Merge pull request #32 from fengjingchao/inst

add check before increment counts and add test for preaccept ok