Fix the way that instance manager finds the version number of instances,
  so that it works properly when the executable name isn't the same as what
  the instance-manager launched, such as when wrapping a libtool-wrapped
  executable from the source tree.

  This removes the 'Ver ' reported in the version column output by
  'SHOW INSTANCE STATUS ...', but the format of this column is not
  documented (and is pretty free-form to begin with).