o fortify() method now has a col.names argument that allows to set
    (some of) the column names of the resulting data.frame.



git-svn-id: svn://svn.r-forge.r-project.org/svnroot/zoo@1011 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
another fix

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/zoo@1012 edb9625f-4e0d-4859-8d74-9fd3b1da38cb