[RobAStBase]: output in kStepEstimator() and oneStepEstimator() is filtered
  by  .checkEstClassForParamFamily(); this allows to return an
  object of S4 class specific to the resp. parametric family (by means of
  S4 method dispatch); this is used in pkg 'RobExtremes' to produce, e.g., 
  objects of class "GEVkStepEstimate", i.e. which inherit from both 
  "kStepEstimate", so that a diag-method for "GEVEstimate" becomes 
  available for this class.

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/robast@780 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
[RobAStBase] qqplot: output is filtered by invisible(); in addition, in the method for kStepEstimate,
   the parametric family is shifted to the return value of the parameter estimate before plotting

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/robast@781 edb9625f-4e0d-4859-8d74-9fd3b1da38cb