Updating the footer for edx.org and open edx.

Making the footer look more like the front page.

* Updated SASS for footer
* Updated HTML for open edx and edx.org templates
* Updated stubbed views
* Added !important SASS to overwrite some blanket LMS styles

Updating steve.m.sandbox.edx.org to have the latest changes.
@wedaly @andywaldrop @dianakhuang @griffresch 

@stephensanchez  you didn't add a override for these in the aws.py file. We need that if this is to be overridden in production?  Is that work in a different PR?

@hkim823 FYI