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


Was `p`'s `width` larger than `100%`? If not, then you don't need this.

OH! I know what this is. You have a `max-width` set on `p` for typography reasons elsewhere. What would you think of pulling this out, and instead, limiting `p`'s `max-width`  where we know we'll have content that needs the restriction (i.e. building specificity instead of doing a lot of overrides to keep track of)? Perhaps `p` inside of an element like `main` or even as limited as an `article` or `section`?

```
p {
  font-family: $whatever;
  main &, .node &, article & {
    // Or whatever selector you think is best
    max-width: 80em;
  }
}