bug fix: 1.modify the auth-required connection as blocking when first connect to redis backends
         2.that when rewrite config file, open the config file only when the new config are OK.
add:  add the version info to the configure.ac file, new version format is:  nutcracker-0.2.4-v0.1  ,the v0.1 mean the first version of modification by IEOD DBA from Tencent
fix some bugs: the result may be memory over-flow
add new command for twemproxy with redis backends: getserver KEY_STRING, by this command you can get the right backend redis
 that the KEY_STRING stored.
modify the auth code, add the log for auth return