.validity.hclust(.., order): as.dendrogram.hclust(): check 'order' only if needed

git-svn-id: https://svn.r-project.org/R/trunk@66853 00db46b3-68df-0310-9c12-caf00c1e9a41
more C++ gotchas

git-svn-id: https://svn.r-project.org/R/trunk@66854 00db46b3-68df-0310-9c12-caf00c1e9a41
tweak reports, add casts

git-svn-id: https://svn.r-project.org/R/trunk@66856 00db46b3-68df-0310-9c12-caf00c1e9a41
update

git-svn-id: https://svn.r-project.org/R/trunk@66857 00db46b3-68df-0310-9c12-caf00c1e9a41