non-join key columns used in j now work again, test added.

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/datatable@1200 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
Added Windows .zip for R-release to homepage (v1.9.3 with fix thanks to Michele)

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/datatable@1201 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
NEWS edit only

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/datatable@1202 edb9625f-4e0d-4859-8d74-9fd3b1da38cb