For example:
  $ be list --status --options
    File "/home/wking/bin/be", line 35, in <module>
      sys.exit(cmdutil.execute(sys.argv[1], sys.argv[2:]))
    File "/home/wking/lib/python2.5/site-packages/libbe/cmdutil.py", line 67, in execute
      get_command(cmd).execute([a.decode(enc) for a in args])
    File "/home/wking/lib/python2.5/site-packages/becommands/list.py", line 36, in execute
      raise Exception, "parsed options"
  Exception: parsed options

The reason for this is that --status takes an argument, so 'be list'
thinks it should list all the bugs with status == "--options".
Ideally what should happen is that an argument-taking option would
check for argument --options, and if so, would raise an exception
returning a list of appropriate completions *for that argument*.
