Fix #1144: Tree: Add dgrid-row-expandable class to parent rows
Fix #1144: Tree: Add dgrid-row-expandable class to parent rows

maier49/dgrid,dylans/dgrid,kfranqueiro/dgrid,kfranqueiro/dgrid,dylans/dgrid,maier49/dgrid,dylans/dgrid,kfranqueiro/dgrid,maier49/dgrid