(Bug 5073) Start converting gradation to Foundation
(Bug 5073) Convert Gradation Horizontal to Foundation

* includes refactoring some code from celerity into the common
  schemes/_nav.scss
(Bug 5073) Convert Gradation Vertical

Involves code changes in other areas as part of moving around shared
styling
(Bug 5073) Clean up Gradation footer styling
Merge pull request #563 from foxfirefey/gradationvertical

Gradationvertical