Squashed '_includes/common/' content from commit 431b050

git-subtree-dir: _includes/common
git-subtree-split: 431b05002a10d79ece959bfdb70b13e6e0554b43
Merge commit '7a4cd088016036e2342d66083aff3796d87b3c33' as '_includes/common'
Add footer to the page with retargeting code.
Broke common repository into common-frontend and common-backend.

Only include the frontend part.
Include the common footer in... the common footer.