Davies Liu: change name of changelog and metadata
Davies Liu: bugfix
Davies Liu: refuse all client commands except STATS
Davies Liu: do not check metalogger if not in master mode
Davies Liu: update sessions when replay changelog and becoming master
Davies Liu: refactor: lastlogversion -> currentlogversion
Davies Liu: send archived changelog to metalogger
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: add mfscgi/run.py.in
Davies Liu: fix help of mfsrun
Davies Liu: accept all incoming connections in one event loop
Davies Liu: bugfix: ignore older changelogs
Davies Liu: fix path of arping
Davies Liu: bugfix: crash if '%' in changelog
Davies Liu: typo