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 

@sarina Yup, I'll add these, but the one link I'm hesitant on is the youtube link; it doesn't exist in the new footer; I could add a setting for it, but it'd be a dead end when we rip this footer out in a week or so.