Matching Rules

  TngUtility.py --list
    no pattern supplied, all server names match

  If a pattern is supplied, it is matched against names by re.search() (re: the regular expression module).
  A name represents a server, a class, a device, a property or an attribute.
  
  Examples: 
    TngUtility.py --list dgg
      matches DGG2, MDGG8

    TngUtility.py --list ^dgg
      matches DGG2

    TngUtility --list omsv --dev 01 --attr position
      matches StepPositionInternal, StepPositionController and many more
      (of Oms devices containing '01')

    TngUtility --list omsv --dev 01 --attr position$
      matches Position, HomePosition, FlagEncoderPosition

    TngUtility --list omsv --dev 01 --attr ^position$
      matches Position