Keep other mappings functional when W/E/K/J are not mapped.

Instead of using `:map` to `W` for the duplicate `<C-Right>` and `L` mappings, duplicate the actual call with :noremap so that they are kept functional when the `W` key is not mapped (`:let g:csv_nomap_w = 1`). I personally don't need three alternatives for the same movement and prefer to keep the built-in W motion.

Also, the `<SID>MoveOver()` function should not rely on the E key mapping.