License year
Fix open <p>
Responsive layout

- Add $wrapper_width to variables
- Breakpoint for pad screens narrower than $wrapper_width
- Breakpoint for mobile screens narrower than $mobile_breakpoint
- Always embed Videos inside iframe and make video size responsive
(snipped borrowed from Bootstrap, see responsive_embed.css.scss)
- Switch to html5 and add viewport tag.
- Add support for css media queries/html5 for older IE