Proposed patch for DNS and name resolution related problems in appliance branch

[Tim Potter]

OK I've been working at this a bit more and have come up with some
performance modifications:

  - Only cache the #1b and #1c names for a very short period of time
    (say 10 seconds) as these names can change quickly especially if
    they are stored on a WINS server.

  - If a cli_connect() fails to a name, clear the cache entry for that
    name.  We don't want to have multiple tries connecting to a cached
    name that doesn't work.


Tim.