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


If we weren't dividing things up into component partials, I'd tend to agree with you, but if we're going to have a file called `_entity-bar.scss`, I think it's easier and more maintainable for new devs, to keep all rules which only have any effect on that component in the component file.

So `_typography.scss` would have global stuff like `p`, or `#{heading()}` or `ul`, but not `.menu`, `.entities` or `footer p`.