CSRF example: Django Rest Framework

[p-frolov]

Can you add following example to documentation
Sourses:
https://gist.github.com/alanhamlett/6316427
https://docs.djangoproject.com/en/dev/ref/csrf/#ajax
I spent some time with this, may be it will be helpful for someone.

    function getCookie(name) {
        var cookieValue = null;
        if (document.cookie && document.cookie !== '') {
            var cookies = document.cookie.split(';');
            for (var i = 0; i < cookies.length; i++) {
                var cookie = jQuery.trim(cookies[i]);
                // Does this cookie string begin with the name we want?
                if (cookie.substring(0, name.length + 1) === (name + '=')) {
                    cookieValue = decodeURIComponent(cookie.substring(name.length + 1));
                    break;
                }
            }
        }
        return cookieValue;
    }

    var ajaxOption = {
        beforeSend: function(xhr, settings) {
            if (settings.type == 'POST' || settings.type == 'PUT' || settings.type == 'DELETE') {
                if (!(/^http:.*/.test(settings.url) || /^https:.*/.test(settings.url))) {
                    // Only send the token to relative URLs i.e. locally.
                    xhr.setRequestHeader("X-CSRFToken", getCookie('csrftoken'));
                }
            }
        }
    };

    var client = new $.RestClient('/api/rest/', {"ajax": ajaxOption});