Partial pick: Cleanup: removed obsolete styling declarations

Pick notes: Just picked the changes for `topcontributors`, `documentation`
    (actually the content of the about page), and one of the changes for
    `#about` (since we dropped all of the `documentation` and we want to
    keep the white background).

Conflicts:
	pootle/static/css/style.css
Followup: Minor adjustments to recover the zoom for the about page
Cleanup: Remove unused template code

We removed this class a few commits before