[RobAStBase/ROptEst] new methods for normtype and biastype for interpolRisk, as well as getRiskFctBV; now cniperPointPlot should work for GPD-type data 

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/robast@762 edb9625f-4e0d-4859-8d74-9fd3b1da38cb