Tab modifications

-Tabs with a single button will no longer create tab navigation.

-Tab color blendings improved.
Various fixes

-Images further optimized.

-Improved example sass in app.scss
Font generation fixes

- fonts.scss now correctly loops through the various weights and
italics.

- Changed some default colors to make them closer to Nu-Connect
Improved spacing output

-No longer extending space classes for deeply nested selectors.

- Made normalize use spacing placeholders.

- Improved box code readability.
Color lightness/darkness fixes

- Lightest/Darkest colors are changed by 35% rather than 40%. Should
make fewer whites and blacks on either end.