FastCFS 5.1 released

After one month of development and test, FastCFS V5.1 has been released, with major improvements including support for IPv6 and bug fixes.

The corresponding git log is as follows:
[fdir & fstore] auto support IPv6 by cluster.conf
[libdiskallocator] check store paths duplicate
[libdiskallocator] call crontab task trunk_index_dump with new thread
[libdiskallocator] trunk_index_dump optimize
[fstore] bugfixed: binlog_check.[hc] set replica's data group id correctly
[fstore] cluster.conf add item use_hash_func to disperse data group distribution

Welcome everyone to test and use V5.1. It is recommended that old users upgrade to the latest version. If you have any questions or suggestions, please feel free to join the group and communicate.