SNSF

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/surveillance@732 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
moved tiaf.exponential() to own source file

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/surveillance@733 edb9625f-4e0d-4859-8d74-9fd3b1da38cb