function _createCategory(sCategory) {
            var welBtnPlusLabel = htElement.welBtnPlusLabel
                .clone()
                .data('category', sCategory)
                .click(_onClickPlusLabel);

            var welCategory = $('#category-template')
                .tmpl({'category': sCategory})
                .append(welBtnPlusLabel);

            welCategory.welBtnPlusLabel = welBtnPlusLabel;
            htElement.aBtnPlusLabel.push(welBtnPlusLabel);

            return welCategory;
        }
Create a category consists with category name, labels belong
to this and plus button to add a label.

@param {String} sCategory
@return {Object} The created category