feature for constants description in prior restored


git-svn-id: svn://svn.r-forge.r-project.org/svnroot/easyabc@377 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
best management of "dontrun" examples


git-svn-id: svn://svn.r-forge.r-project.org/svnroot/easyabc@378 edb9625f-4e0d-4859-8d74-9fd3b1da38cb