Fix for #5366 - setkey works properly on data.table containing list columns. Tests added.

git-svn-id: svn+ssh://svn.r-forge.r-project.org/svnroot/datatable@1216 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
A new separate `?setDT`. Cleaned up `?setkey`.

git-svn-id: svn+ssh://svn.r-forge.r-project.org/svnroot/datatable@1217 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
Closes #5408 - order of columns were sometimes reversed with as.data.table.table. Tests added.

git-svn-id: svn+ssh://svn.r-forge.r-project.org/svnroot/datatable@1218 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
Minor corrections to '?setorder'.

git-svn-id: svn+ssh://svn.r-forge.r-project.org/svnroot/datatable@1219 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
Added type name to error message in Creorder

git-svn-id: svn+ssh://svn.r-forge.r-project.org/svnroot/datatable@1220 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
'setorder' now retains key if order doesn't change.

git-svn-id: svn+ssh://svn.r-forge.r-project.org/svnroot/datatable@1221 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
More minor clarifications in 'setorder'.
Added `?setattr` (which also contains `setnames`). This makes `?setkey` standalone. Other set* functions are not buried within setkey anymore.
Added `?setattr` (which also contains `setnames`). This makes `?setkey` standalone. Other set* functions are not buried within setkey anymore.
Merge branch 'refs/heads/r-forge-git-svn-local'

Conflicts:
	pkg/src/reorder.c