Create an edit log at the given dir location.
You should never have to load an existing log. If there is a log at
startup, it should have already been processed and deleted by the time the
WAL object is started up.
fs - filesystem handle
rootDir - path to where logs and oldlogs
logDir - dir where wals are stored
archiveDir - dir where wals are archived
conf - configuration to use
listeners - Listeners on WAL events. Listeners passed here will
be registered before we do anything else; e.g. the
failIfWALExists - If true IOException will be thrown if files related to this wal
prefix - should always be hostname and port in distributed env and
it will be URL encoded before being used.
If prefix is null, "wal" will be used
suffix - will be url encoded. null is treated as empty. non-empty must start with