Grid and type changes

@tsmith512 

When you have a chance to review this, please let me know what you think. I'm hoping this will be a much smoother transition to Drupal.

## Key changes
* Breakpoints have been adjusted/removed/redefined based on a mobile-first approach to breakpoint design
* Removed em() function - changed $space variable and type measurement unit to pixels
* Changed footer seal to use suggest background-image SVG over inline SVG

## Still to-to
* Fix ```ul``` and ```ol``` ```list-type``` for drupals
* Refine entity bar and search for mobile


I think we should stick with `background-size: contain` instead of `cover` because `cover` will expand the image to fill the entire box, even if it means cropping off one dimension. Since this is their logo, we should avoid that. If you're running into something weird, it could indicate my math is off, though.