add basic functionality for meta-analysis

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/metamisc@227 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
add example data

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/metamisc@228 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
add requirements pROC package

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/metamisc@229 edb9625f-4e0d-4859-8d74-9fd3b1da38cb