Numerous changes and tests
Grid Updates

- Created a function to allow the use of grids other than 12.

- Moved all user-defined variables to config.scss

- Moved many placeholder selectors inside the responsive grid
framework, allowing for various extensions based on breakpoints.

- Moved colors to colors/_colors.scss, which is now imported by
_variables.scss.

- Fixed color shading definitions.

- Added variables for animations.
Merge branch 'nu_connect-' into gh-pages
- Made clear fix mandatory for floated grids.

- Added ability to make base-lineheight smaller than font-size,
allowing type to line up on a more granular baseline.

- Added Link color variable.

- Fixed darker-color variables.

- Made button mixin a little easier to manage.

- Moved grid variables into _variables.scss

- Improved body font-size/lineheight calculation.

- Moved island/media block to extend.scss

- Made type-space-sc mixin more efficient by removing unnecessary third
and fourth values.
Merge branch 'nu_connect-' into gh-pages