Feature/confirm classes

Adding extra styling and positional control for the confirm method.

Do you take contributions on this project? I just haven't heard any feedback on issue or pull request.

I do sometimes, it depends. Thanks for doing this work. To be honest I'm not sure if I'll incorporate the style portion but you bring up a great point about the confirm button positions being changeable.

I'd love to see this merged. I need to style the confirm button differently for one particular confirm notie (It's an 'are you sure you want to delete that?' dialog box, with a red 'Delete' button as the confirm button).

Currently the only want I can achieve this is to change the global notie options for the 'backgroundSuccess' class, and then change it back to the default class after this particular confirm box is dismissed.

      `notie.setOptions({
            classes: {
                backgroundSuccess: 'notie-background-delete'
            }
        });

        function resetNotie() {
            notie.setOptions({
                classes: {
                    backgroundSuccess: 'notie-background-success'
                }
            });
        }`