viced: Add support for -config and -logfile options

Add options to the fileserver to specify alternate locations for
the log file and the config.  This will be useful for testing
purposes.

Change-Id: I3550bd993fe5fd2cd9b90425962c95cb1c7d98ea
Reviewed-on: http://gerrit.openafs.org/9830
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@your-file-system.com>