dimnames(), notably names(dimnames()) -- primarily in connection with symmpart(), skewpart() and forceSymmetric()

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/matrix@3020 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
update

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/matrix@3021 edb9625f-4e0d-4859-8d74-9fd3b1da38cb