dsorted and csorted now used in forder's column loop as well,  passes checks and timings.

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/datatable@1128 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
forder=data.table:::forder added to tests.Rraw to pass R CMD check

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/datatable@1129 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
setkey switched to forder

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/datatable@1130 edb9625f-4e0d-4859-8d74-9fd3b1da38cb