revisions

don't need #modal-desc style, just use .invis instead

not just video, but iframe specific comment

remove demo styling css from modal css file, add to head of demo html.

rename js only button classes to have prefixed "js-"

rename btn-start to js-btn

rename m-video to js-m-iframe, rename m-ajax to js-m-ajax, rename m-reg to js-m-template in html and js