Slugify: Remove acentos e caracteres não permitidos em urls, substitui espaços, underlines e caracteres não alfanuméricos por hífen.

slugify.js

String.prototype.slugify = function(){
    return (this)
        .replace(/[ÁÀÂÃÄ]/gi, 'a')
        .replace(/[ÉÈÊË]/gi, 'e')
        .replace(/[ÍÌÎÏ]/gi, 'i')
        .replace(/[ÓÒÔÕÖ]/gi, 'o')
        .replace(/[ÚÙÛÜ]/gi, 'u')
        .replace(/[Ç]/gi, 'c')
        .toLowerCase() // change everything to lowercase
        .replace(/^\s+|\s+$/g, '') // trim leading and trailing spaces
        .replace(/[_|\s]+/g, '-') // change all spaces and underscores to a hyphen
        .replace(/[^a-z0-9-\/]+/g, '') // remove all non-alphanumeric characters except the hyphen and bar
        .replace(/[-]+/g, '-') // replace multiple instances of the hyphen with a single instance
        .replace(/^-+|-+$/g, '') // trim leading and trailing hyphens
        ;
};