fixed cph eps level

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/riskscore@104 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
added missing docs and fixed args in ipcw.cox

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/riskscore@105 edb9625f-4e0d-4859-8d74-9fd3b1da38cb