mixin svg(id, viewbox, className)
if viewbox
svg(viewbox='#{viewbox}', class!=className)
use(xlink:href='assets/img/sprite.svg#' + id)
else
svg(viewbox='0 0 50 50', class!=className)
use(xlink:href='assets/img/sprite.svg#' + id)
//- Usage: +svg('symbolID', 'viewbox parameters', 'classnames')