Allow symbols for controller/action pair

According to the docs, controller/action pair can be used with symbols, but its not working.
```
Controller/Action Pair -> [[:controller], [:action_a, :action_b]]
```

The examples shows it should be use as strings:
```
active_link_to 'User Edit', edit_user_path(@user), active: [['people', 'news'], ['show', 'edit']]
```

It's confused when you can use `[controller: :action]`, but not `[[:controller], [:action]]`.