more getting rid of intermediate results (a follow up on r821)

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/coin@842 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
'friedman_test' didn't warn when weights were supplied (fixed in r839)

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/coin@843 edb9625f-4e0d-4859-8d74-9fd3b1da38cb