Performance improve oxygen

Tickets posted on the oxygen issue tracker:
https://github.com/soflyy/oxygen-bugs-and-features/issues/761
https://github.com/soflyy/oxygen-bugs-and-features/issues/755
https://github.com/soflyy/oxygen-bugs-and-features/issues/18
https://github.com/soflyy/oxygen-bugs-and-features/issues/686

This to prevent loading all css classes in unviersal and globally even if not used on the page.