Use encoding argument for conversion via iconv()


git-svn-id: svn://svn.r-forge.r-project.org/svnroot/tm@1325 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
Default to encoding of the current locale


git-svn-id: svn://svn.r-forge.r-project.org/svnroot/tm@1326 edb9625f-4e0d-4859-8d74-9fd3b1da38cb