new version; extensive doc thru roxygen2, bug fixes, new args to gendistance

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/nbpmatching@17 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
adding package file for roxygen

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/nbpmatching@18 edb9625f-4e0d-4859-8d74-9fd3b1da38cb