Localizernode hook_menu not specifc to nodes with IDs

The hook_menu entry in localizernode.module is not specific to nodes with IDs, and just happens not to show up because no other tabs show up on these nodes. It would be safer to check arg(0) for 'node' and that arg(1) is numeric. This way when other modules make the same mistake, the Localizer 'Translations' tab doesn't show up with them.

patch attached