Davies Liu: fix fs_ismastermode(), reload order is reversed as init
Davies Liu: fix archived changelog, drop '\n', skip empty file
Davies Liu: disable fsync() to speed up download metadata
Davies Liu: adjust order of mastercomm, replay changelog first.
Davies Liu: add tool mfsrun: failover for mfsmaster

based on zookeeper, need kazoo
Davies Liu: accept all incoming connections in one event loop
Davies Liu: bugfix: ignore older changelogs
Davies Liu: bugfix: crash if '%' in changelog
Davies Liu: typo