ubik: Use supplied config directory in ugen

ubik: Use supplied config directory in ugen

ugen_ClientInit permits the configuration directory to use to be
passed on the command line. However, it was then promptly overwritting
the supplied directory with the standard client (or server) directories,
depending on whether localauth was in use or not.

As a start to fixing this anti-social behaviour, modify ugen so that if
we're not doing localauth, and if the caller has passed us a config
directory, use that instead of the system default one. This allows us to
start creating test harnesses for our command line tools.

Change-Id: I6916389ce56df4cee62845a03282c5c10d3095eb
Reviewed-on: http://gerrit.openafs.org/4809
Reviewed-by: Jeffrey Altman <jaltman@openafs.org>
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>