code: function selectorToId(selector) {
          var id = selector.replace(/[^a-z0-9_-]/ig, "_");
  
          if (styledoc.item_id_trim_underscores) {
              id = id.replace(/_{2,}/g, "_").replace(/^_/, "").replace(/_$/, "");
          }
  
          return id;
      }
docs: Replace any char other than latin letters, digits, hyphens and underscores with underscore char
  Also wipes out the first underscore char (@todo is it really good and safe idea?)
  E.g.: .my-class => my-class
  .my-class.subclass#id #otherid => my-class_subclass_id__otherid
  @param {string} selector
  @returns {string}