Update rails.html.erb

You get the error - File to import not found or unreadable: foundation/common/ratios 
if you don't have the compass-rails gem
Tighten up the Rails feature detection to deal with Rails 2 apps that have Sprockets installed as seperate middleware.
Merge pull request #2621 from asecondwill/patch-1

Update rails.html.erb
Merge pull request #2631 from polleverywhere/master

Rails 2 compatability
Update foundation.topbar.js

on scroll, fixed class was never removed.
changed comparison from distance

All credits to iamjonatha see issue #2564