fix doc for treewalk

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/phylobase@889 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
fix docs

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/phylobase@890 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
remove exotic calls that failed with Prof. Ripley's compilers

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/phylobase@891 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
update DESCRIPTION file

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/phylobase@892 edb9625f-4e0d-4859-8d74-9fd3b1da38cb