Squashed commit:

+ Fixed a bug when using 'subset' argument to dcast.data.table. Added tests. Dint update NEWS as it's due to changes to dcast in 1.9.3.
+ Added anyDuplicated alias to ?duplicated (was a warning in R-forge check).

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/datatable@1239 edb9625f-4e0d-4859-8d74-9fd3b1da38cb