[RobExtremes] revised interpolation scripts

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/robast@800 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
[RobExtremesBuffer] first intermediat results on our way to produce comprehensive interpolation grids in case GEVMuUnknown as well

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/robast@801 edb9625f-4e0d-4859-8d74-9fd3b1da38cb