dperm for approximate test returned non-zero probabilities for values not included in the support

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/coin@872 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
preparation for coming changes

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/coin@873 edb9625f-4e0d-4859-8d74-9fd3b1da38cb