:racehorse: Use DOM APIs to apply stylesheets

Previously jQuery was used, but using the DOM APIs directly
takes 1/3 of the time.
Preserve ordering within type class
Store sheet before it goes away
Update specs to expect an element
Remove unused require
:lipstick: Sort requires
:memo: Emit -> Emitted
:lipstick: e -> error
Remove nulled variable
:lipstick: Use proper Less
Merge pull request #3470 from atom/ks-no-jquery-to-apply-stylesheets

Use DOM APIs to apply stylesheets